user9724: Here is my run command:
cgminer -o stratum+tcp://coinotron.com:3334 -u user -p pass --scrypt

the only output in my terminal I get is (and only this):
[2013-11-30 11:34:02] Started cgminer 3.7.2

if Ctrl+C it I finally get this output:
[2013-11-30 11:34:43] Summary of runtime statistics:
[2013-11-30 11:34:43] Started at [2013-11-30 11:34:03]
[2013-11-30 11:34:43] Pool: stratum+tcp://coinotron.com:3334
[2013-11-30 11:34:43] Runtime: 0 hrs : 0 mins : 40 secs                     
[2013-11-30 11:34:43] Average hashrate: 0.0 Kilohash/s                
[2013-11-30 11:34:43] Solved blocks: 0                     
[2013-11-30 11:34:43] Best share difficulty: 0                     
[2013-11-30 11:34:43] Share submissions: 0                     
[2013-11-30 11:34:43] Accepted shares: 0                     
[2013-11-30 11:34:43] Rejected shares: 0                     
[2013-11-30 11:34:43] Accepted difficulty shares: 0                   
[2013-11-30 11:34:43] Rejected difficulty shares: 0                   
[2013-11-30 11:34:43] Hardware errors: 0                     
[2013-11-30 11:34:43] Utility (accepted shares / min): 0.00/min       
[2013-11-30 11:34:43] Work Utility (diff1 shares solved / min): 0.00/min
[2013-11-30 11:34:43] Stale submissions discarded due to new blocks: 0
[2013-11-30 11:34:43] Unable to get work from server occasions: 0                 
[2013-11-30 11:34:43] Work items generated locally: 1                 
[2013-11-30 11:34:43] Submitting work remotely delay occasions: 0     
[2013-11-30 11:34:43] New blocks detected on network: 1
[2013-11-30 11:34:43] Summary of per device statistics:
[2013-11-30 11:34:43] GPU0     | (5s):0.000 (avg):0.000h/s | A:0 R:0 HW:0 WU:0.0/m

my GPU is properly detected:
11:34:56 me@ArchPC::~/Desktop cgminer -n
 [2013-11-30 11:36:35] CL Platform 0 vendor: NVIDIA Corporation                    
 [2013-11-30 11:36:35] CL Platform 0 name: NVIDIA CUDA                    
 [2013-11-30 11:36:35] CL Platform 0 version: OpenCL 1.1 CUDA 6.0.1                    
 [2013-11-30 11:36:35] Platform 0 devices: 1                    
 [2013-11-30 11:36:35]  0   GeForce 9600 GT                    
 [2013-11-30 11:36:35] 1 GPU devices max detected                    
 [2013-11-30 11:36:35] USB all: found 6 devices - listing known devices                    
 [2013-11-30 11:36:35] No known USB devices

What could the problem be?
EDIT: Just tried it without --scrypt... it works then, but I need scrypt for LTC. How do I fix this?

user11099: Make sure your bat file has these two lines first
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1


user9986: Apparently I do not have enough points yet to give your answer a vote, but your solution also worked for me! Adding -T to the command line command did the trick. Not only do I now get a neat output of what is happening; the -T parameter also made the entire mining process actually work!
Before adding the -T command:
Screen flashed with the "Started CGMiner 3.7.2" message.
No messages were shown until I pressed CTRL + C.
The report said that only one share had been submitted and accepted - every time I ran CGMiner.
After adding the -T command:
The screen doesn't flash any more. 
Everything that happens is outputted line by line to my command prompt.
CGMiner is actually working and submitting shares. As we speak I'm on a total of 3616 accepted difficulty shares, contrary to 32 before.

9724: <p>Here is my run command:</p>

<pre><code>cgminer -o stratum+tcp://coinotron.com:3334 -u user -p pass --scrypt
</code></pre>

<p>the only output in my terminal I get is (and only this):</p>

<pre><code>[2013-11-30 11:34:02] Started cgminer 3.7.2
</code></pre>

<p>if <kbd>Ctrl+C</kbd> it I finally get this output:</p>

<pre><code>[2013-11-30 11:34:43] Summary of runtime statistics:
[2013-11-30 11:34:43] Started at [2013-11-30 11:34:03]
[2013-11-30 11:34:43] Pool: stratum+tcp://coinotron.com:3334
[2013-11-30 11:34:43] Runtime: 0 hrs : 0 mins : 40 secs                     
[2013-11-30 11:34:43] Average hashrate: 0.0 Kilohash/s                
[2013-11-30 11:34:43] Solved blocks: 0                     
[2013-11-30 11:34:43] Best share difficulty: 0                     
[2013-11-30 11:34:43] Share submissions: 0                     
[2013-11-30 11:34:43] Accepted shares: 0                     
[2013-11-30 11:34:43] Rejected shares: 0                     
[2013-11-30 11:34:43] Accepted difficulty shares: 0                   
[2013-11-30 11:34:43] Rejected difficulty shares: 0                   
[2013-11-30 11:34:43] Hardware errors: 0                     
[2013-11-30 11:34:43] Utility (accepted shares / min): 0.00/min       
[2013-11-30 11:34:43] Work Utility (diff1 shares solved / min): 0.00/min
[2013-11-30 11:34:43] Stale submissions discarded due to new blocks: 0
[2013-11-30 11:34:43] Unable to get work from server occasions: 0                 
[2013-11-30 11:34:43] Work items generated locally: 1                 
[2013-11-30 11:34:43] Submitting work remotely delay occasions: 0     
[2013-11-30 11:34:43] New blocks detected on network: 1
[2013-11-30 11:34:43] Summary of per device statistics:
[2013-11-30 11:34:43] GPU0     | (5s):0.000 (avg):0.000h/s | A:0 R:0 HW:0 WU:0.0/m
</code></pre>

<p>my GPU is properly detected:</p>

<pre><code>11:34:56 me@ArchPC::~/Desktop cgminer -n
 [2013-11-30 11:36:35] CL Platform 0 vendor: NVIDIA Corporation                    
 [2013-11-30 11:36:35] CL Platform 0 name: NVIDIA CUDA                    
 [2013-11-30 11:36:35] CL Platform 0 version: OpenCL 1.1 CUDA 6.0.1                    
 [2013-11-30 11:36:35] Platform 0 devices: 1                    
 [2013-11-30 11:36:35]  0   GeForce 9600 GT                    
 [2013-11-30 11:36:35] 1 GPU devices max detected                    
 [2013-11-30 11:36:35] USB all: found 6 devices - listing known devices                    
 [2013-11-30 11:36:35] No known USB devices
</code></pre>

<p>What could the problem be?</p>

<p>EDIT: Just tried it without <code>--scrypt</code>... it works then, but I need scrypt for LTC. How do I fix this?</p>
 11099: <p>Make sure your bat file has these two lines first</p>

<pre><code>setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
</code></pre>
 9986: <p>Apparently I do not have enough points yet to give your answer a vote, but your solution also worked for me! Adding -T to the command line command did the trick. Not only do I now get a neat output of what is happening; the -T parameter also made the entire mining process actually <strong>work</strong>!</p>

<p><strong>Before adding the -T command:</strong>
Screen flashed with the "Started CGMiner 3.7.2" message.
No messages were shown until I pressed CTRL + C.
The report said that only one share had been submitted and accepted - <em>every time</em> I ran CGMiner.</p>

<p><strong>After adding the -T command:</strong>
The screen doesn't flash any more. 
Everything that happens is outputted line by line to my command prompt.
CGMiner is actually <em>working and submitting shares</em>. As we speak I'm on a total of 3616 accepted difficulty shares, contrary to 32 before.</p>
