I keep two development enviroments for a chunk of web software I've been working on, one locally and one remotely on the company dev server.
I'm working on my local copy (faster SSHing) and change a very simple feature, it was something related to what a function printed back out into the HTML, and I set the monster running - and nothing. No changes.
I go and look at the code again... Confused. So I stick a 'print STDERR "Value $var\n"' in there, to make sure my var is what I expect it to be, run the CGI again via the browser... Nada. Nothing in the error log. I think about this for a bit and decide that, yes, I've done something really dumb.
I just can't see it. I don't get it... So, I walk away for 15 minutes and take a break.

Return. Think. Think. Look at the access logs - and its not even being touched?
Decide I'd better double check the URL... Sure enough. I had somehow switched over accidentally from the local copy to the dev copy I hadn't been working on.

So banal when you work it out. So damned frustrating when you're right there wondering what kind of moronic cock-up you've just made.

JP,
-- Alexander Widdlemouse undid his bellybutton and his bum dropped off --