Hi. Here's a guess on your problem.
I had a similar problem the other day. A file that had been working for a long time suddenly stopped working, right after I uploaded and overwrote it. The error log said "fopen permission denied" or something like that, so it wasn't a syntax problem.
To make a long story short, my FTP client was telling me that it was set to have execute permissions, but it didn't really have execute permissions. I refreshed a number of times, and it still showed that it had execute permissions, but it really didn't.
Here's what I'd do if I were you: Place the following in your Perl code, at the very start of your code (at the very start of where you actually start issuing commands)
Upload it to your server, and execute the script.
Then check your error log and see if it mentions "somethingunique".
If it doesn't, then it means that it hasn't even made it to the first command/expression/statement. In that case, it's probably a file permissions thing.
Hope that helps,