Today, I was in the unwieldy business of compiling Java code on my machine and testing the class files on another deployment (on different machine no less.) And Eclipse decided roil the already muddy waters. I placed class files on the server multiple times but never saw my changes come through. Double checked everything - times stamp on the class file, was I copying it to the correct folder, was my ftp client screwing up, did my Tomcat have the latest ... nothing seemed to work.

Finally I checked file sizes. Eclipse was dishing out crap as compiled files. "Clean" took out the old files, but the supposedly latest class files actually seemed to be generated from old code. It was particularly insidious behaviour not to warn me about this. Sometimes the classes just would not be there after a "clean + compile". And the problem disappeared just as it had arrived - without me doing anything about it . Other possibly relevant information - I had a couple of related projects (as opposed to jars). Moral of the story - Eclipse ain't perfect. Its capable of throwing a spanner in the works. Quietly at that.