Adobe CS File Corruption on OS X 10.5.3
A little warning for anyone out there running OS X Leopard 10.5.3 and using any of the Adobe CS products to edit files on a remote or network server: beware of file corruption.
Folks started picking up on this last month when the 10.5.3 update was released. According to AppleInsider:
When users attempt a save command, the file on the server becomes unusable, even when copied and opened locally. The issue occurs regardless of the format and doesn't appear to occur for locally saved files, which can still be uploaded to the server afterwards. The corrupted files appear to have a modified header that prevents them from being recognized properly.
We all work off of a file server in the office. Unfortunately, this bug reared its ugly head and rendered a few Photoshop documents useless. Luckily, we pulled files off our daily backup, so not all was lost. However, we're anxiously awaiting the fix from Apple included with OS X 10.5.4, which should be released in July prior to the iPhone 3G launch. Until then, to all those working with said configuration: copy your files locally before make any changes.
Update: Apple has released the OS X 10.5.4 update, which should resolve the issues described above. Upgrade your OS today.

this is real, it happened to me.
File corruption -- it's no laughing matter.
happened in our office too
ditto...someone needs to tighten up.
This would have never happened if we ran Windows.
@Michael http://tinyurl.com/yq28pv
10.5.4 is out, 'posed to fix it
We've all updated here. I haven't tested it a lot yet, but I'm pretty sure they resolved it. At least, I hope so.