Storing PST files on Windows fileserver is bad idea just like that KB article says. I've seen it and it's actually more evil than just being slow. It causes drive mappings to stall for anything from few seconds to over minute. Since Windows clients always search dlls, exes etc. first from your homeshare all workstations stop working for same period of time. There's nothing on logs, no error messages, no suspicious perfmon values, no errors visible with network sniffer. PC's and server will just pause for that 1 second to 1+ minute. That's with dualcore CPU, several gigabytes of ram, hardware RAID 1+0, dual gigabit network etc. with only ~50 users. You'll also start seeing filesystem corruption. Not files itself, but ownership and permissions get mangled. There's hotfix MS is trying to hide that fixes this corruption... Well anyway it's fixed on Win2003 SP2 so they don't need to admit it anymore just suggest installing SP2.