Home Directories/font cache corruption

Question

I have a network of about 30+ Macs which all have their user folders served from OS X Server (10.4.1). Users login to their accounts over the network from their systems sitting on their desks. The computers vary, Mac Minis, iMac G4s and iMac G5s.
All was very well until we upgraded all the workstations from 10.3.9 and 10.4.x to 10.4.5 then we started seeing trickles of font cache corruption. Now it's like an epidemic, everyone is seeing or has seen the problem, some just randomly, some everyday, some multiple times a day. It doesn't matter what hardware they are using.
One user in particular sees the problem everyday, sometimes a couple of times. For instance, at lunch they log out, leave the machine, come back and log in. Somwhere in that process the font cache becomes corrupt and Mail, Safari and Filemaker Pro 7 all exhibit font display problems.
I temporarily fix them by booting their system into Safe Mode and logging in as them which moves the font cache to the trash. I'll also delete com.apple.ATS out of /Library/Caches.
Some systems have had multiple fonts (I presume thanks to MS Office) and I'll resolve those with Font Book, I'll also validate the fonts and delete any that Font Book has flagged as unusable. I've even resolved fonts while in Safe Boot but the problem still persists.
I've even gone as far as just replacing the system with a new one in addition to ClamAV virus scans. There are never any virus' found and the problem evenually comes back.
Any ideas?

Answer 1

I saw this same problem when we upgraded to TIger last month. Fonts in Filemaker and a few other apps would appear garbled, and Word would report almost every font as corrupted. The fix was to delete the folder /Library/Caches/com.apple.ATS/ from the client machine and restart. My solution was to create a launchd .plist file that deletes the font cache folder when the client machine boots up, and also deletes the folder every morning at 2:30 A.M. just to be safe. I installed the launchd file on every client computer in /System/Library/LaunchDaemons/ and this seemed to solve the problem. I instructed our users to restart their computer if they were experiencing font problems and i haven't had any more complaints. Here is the plist file that i use: (I made it using Launchd Editor http://www.codepoetry.net/products/launchdeditor)
!!!BEGIN fontcacheclear.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Label</key>
<string>fontcacheclear</string>
<key>Program</key>
<string>/bin/rm</string>
<key>ProgramArguments</key>
<array>
<string>/bin/rm</string>
<string>-rf</string>
<string>/Library/Caches/com.apple.ATS/</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>StandardErrorPath</key>
<string>/Library/Logs/fontcacheclear.log</string>
<key>StandardOutPath</key>
<string>/Library/Logs/fontcacheclear.log</string>
<key>StartCalendarInterval</key>
<dict>
<key>Hour</key>
<integer>2</integer>
<key>Minute</key>
<integer>30</integer>
</dict>
<key>UserName</key>
<string>root</string>
</dict>
</plist>
!!!END
1.8 DP G5   Mac OS X (10.4.6)  
1.8 DP G5   Mac OS X (10.4.6)