user4439: I'm giving a specific case here, but I think I have seen the same error trying to use stratum_proxy for any pool and coin I have tried.
When wemineltc.com briefly had a getwork server up, cudaminer worked great! But now that they're back to stratum only, I'm trying to get that to work.
I run the stratum proxy that I get from wemineltc and see this:
C:\dev\cudaminer-2013-04-14\stratum_proxy.exe\twisted\web\util.py:372: Deprecati
onWarning: Passing filenames or file objects to XMLFile is deprecated since Twis
ted 12.1.  Pass a FilePath instead.
2013-04-16 08:24:07,302 WARNING proxy jobs.<module> # C extension for midstate n
ot available. Using default implementation instead.
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Stratum proxy version: 1.
3.0
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Trying to connect to Stra
tum pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Setting PoW algo: scrypt
2013-04-16 08:24:07,621 INFO stats stats.print_stats # 1 peers connected, state
changed 1 times
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Connected to Stratu
m pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Subscribing for min
ing jobs
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # PROXY IS LISTENING ON ALL
 IPs ON PORT 3333 (stratum) AND 8332 (getwork)
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy client_service.handle_event # Setting new dif
ficulty: 128
2013-04-16 08:24:07,839 INFO proxy client_service.handle_event # New job c9 for
prevhash d2c7e1c2, clean_jobs=True

Then I run cudaminer with the following batch file (on windows 7 64 bit):
cudaminer.exe -o 127.0.0.1:8332 -O user:password

And see this:
C:\dev\cudaminer-2013-04-14>cudaminer.exe -o http://127.0.0.1:8332 -O user:
password
           *** CudaMiner for nVidia GPUs by Christian Buchner ***
                     This is version 2013-04-14 (alpha)
        based on pooler-cpuminer 2.2.3 (c) 2010 Jeff Garzik, 2012 pooler
               Cuda additions Copyright 2013 Christian Buchner
           My donation address: LKS1WDKGED647msBQfLBHV3Ls8sveGncnm

[2013-04-16 08:29:52] 1 miner threads started, using 'scrypt' algorithm.
[2013-04-16 08:29:52] HTTP request failed: The requested URL returned error: 401

[2013-04-16 08:29:52] json_rpc_call failed, retry after 15 seconds

I have tried a few different things but I always get that 401 error. Any ideas on resolving this?

user4439: The problem was with windows firewall. Turned it off, tried again, it worked. Turned it back on and set the appropriate windows firewall exceptions for stratum_proxy and cudaminer and it worked.
I had this problem suddenly appear again this morning. Turning off firewall made no difference. I changed cudaminer to point to my machine ip address instead of 127.0.0.1 and then it started working.

4439: <p>I'm giving a specific case here, but I think I have seen the same error trying to use stratum_proxy for any pool and coin I have tried.</p>

<p>When wemineltc.com briefly had a getwork server up, cudaminer worked great! But now that they're back to stratum only, I'm trying to get that to work.</p>

<p>I run the stratum proxy that I get from wemineltc and see this:</p>

<pre><code>C:\dev\cudaminer-2013-04-14\stratum_proxy.exe\twisted\web\util.py:372: Deprecati
onWarning: Passing filenames or file objects to XMLFile is deprecated since Twis
ted 12.1.  Pass a FilePath instead.
2013-04-16 08:24:07,302 WARNING proxy jobs.&lt;module&gt; # C extension for midstate n
ot available. Using default implementation instead.
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Stratum proxy version: 1.
3.0
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Trying to connect to Stra
tum pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,302 INFO proxy mining_proxy.main # Setting PoW algo: scrypt
2013-04-16 08:24:07,621 INFO stats stats.print_stats # 1 peers connected, state
changed 1 times
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Connected to Stratu
m pool at eu.wemineltc.com:3333
2013-04-16 08:24:07,621 INFO proxy mining_proxy.on_connect # Subscribing for min
ing jobs
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # PROXY IS LISTENING ON ALL
 IPs ON PORT 3333 (stratum) AND 8332 (getwork)
2013-04-16 08:24:07,838 INFO proxy mining_proxy.main # -------------------------
----------------------------------------------
2013-04-16 08:24:07,838 INFO proxy client_service.handle_event # Setting new dif
ficulty: 128
2013-04-16 08:24:07,839 INFO proxy client_service.handle_event # New job c9 for
prevhash d2c7e1c2, clean_jobs=True
</code></pre>

<p>Then I run cudaminer with the following batch file (on windows 7 64 bit):</p>

<pre><code>cudaminer.exe -o 127.0.0.1:8332 -O user:password
</code></pre>

<p>And see this:</p>

<pre><code>C:\dev\cudaminer-2013-04-14&gt;cudaminer.exe -o http://127.0.0.1:8332 -O user:
password
           *** CudaMiner for nVidia GPUs by Christian Buchner ***
                     This is version 2013-04-14 (alpha)
        based on pooler-cpuminer 2.2.3 (c) 2010 Jeff Garzik, 2012 pooler
               Cuda additions Copyright 2013 Christian Buchner
           My donation address: LKS1WDKGED647msBQfLBHV3Ls8sveGncnm

[2013-04-16 08:29:52] 1 miner threads started, using 'scrypt' algorithm.
[2013-04-16 08:29:52] HTTP request failed: The requested URL returned error: 401

[2013-04-16 08:29:52] json_rpc_call failed, retry after 15 seconds
</code></pre>

<p>I have tried a few different things but I always get that 401 error. Any ideas on resolving this?</p>
 4439: <p>The problem was with windows firewall. Turned it off, tried again, it worked. Turned it back on and set the appropriate windows firewall exceptions for stratum_proxy and cudaminer and it worked.</p>

<p>I had this problem suddenly appear again this morning. Turning off firewall made no difference. I changed cudaminer to point to my machine ip address instead of 127.0.0.1 and then it started working.</p>
