OSX 10.3.4 Finder mis-reporting file dates

I've been modifying source code files (I'm a programmer using CodeWarrior-Pascal), and at the end of the day, when I look in the Finder, my modified files are there correctly, but the file dates have not been updated.

If I select a file in question, the date immediately updates in the Finder to the correct date ("today"), and that particular file is fixed.

A sort by dates is wrong is wrong as well. I need to manually update the files by clicking on them.

My friend has the same bug on 10.2 OSX, also a CodeWarrior-Pascal programmer. But of course the issue is in the Finder, not Code Warrior.

Has anyone heard of this weird OSX Finder bug?