Q:

Apache Commons FTP: isPositivePreliminary returns false (code 550)

I'm using Apache Commons' FTPClient to talk to an FTP server and upload some file. Inside the code, I discovered that the function isPositivePreliminary() returns false, because the reply code it gets is 550. The same code acts differently (with no problems) accessing other FTP sites.
However, when I try to open a regular FTP connection in shell with the same address, user and password - everything works just fine: going into passive mode, uploading and renaming a file.
So what gives? Why can't my code access it? I'm guessing it's something in the remote FTP configuration, but what do I need to tell my customer?

A:

I know what it is (for future reference): Error 550 states that "The filename, directory name, or volume label syntax is incorrect.". In my code, I tried uploading a file that had colons in its name, which this particular FTP server didn't like.
-dbg

