same issue here... 10.5.3 client, 10.4 tiger server, CS3. PSD files corrupt when saving to the server, not locally. We repaired permissions on the client. Re-propagated permissions on the share on the server. Re-installed photoshop. No help. Been reading everywhere... only solution until Apple or Adobe comes up with an official fix is to save locally, copy to server via finder.
As a general rule of thumb, this is just another reason why we don't upgrade OS's or anything for that matter until it's been out for at least a year. There's always crap like this that happens and wastes so much time and effort.
Our office is all 10.4 client and server still, except this one Mac Pro (preinstalled with Leopard) we recently bought that will not allow you to downgrade/reinstall 10.4 on it. I remember when we upgraded our office from 10.3 to 10.4, we waited until 10.4.6 was out, because of all the issues they had when 10.4 was first released... same thing again. I'm not even considering Leopard until 10.5.6. The only thing that really stinks is that new Mac's will not let you install an older version of the OS on them, even if you do a complete wipe and start from scratch. Kinda crazy!
10.5.4 Has fixed the Photoshop CS3 Problem on our system. It specifically mentions it in apples bugs fixes on the update. We have since tried saving versions and all appears fine. Unfortunately it does not help with files that are already damaged.
10.5.4 fixed the problem. we were lucky...out of 15 designers only 2 had a series of corrupt Photoshop files (one designer still ruined a file even after I warned them to not work off of the server!).
We're good to go.
BTW the RAW import fix thingy didn't work for us. The files are gone forever.