I'm running FMP over a small LAN (10BT). The host machine periodically freezes with a network arrow cursor or coffee cup and has to be rebooted. Seems to occur most often when a client queries the host with a find request, but at other times as well. Definitely more frequent than in the past but I can't tie it to any changes made.
In an attempt to fix, I've clean-installed systems 8.6 on host and suspect client (also rebuilt desktops, zapped PRAMs, checked with Norton and Disk First Aid) and reinstalled FMP 4 upgraded to 4.0v2.
Host is Performa 6400, sufficient RAM and disk space, Farallon 10/100BT NIC. Primary client is same with Sonnet G3 240 upgrade and recent extension (1.4, I think.) Hub is 5 port 10BT by Dlink.
Also on the LAN is a funky collection of older hardware, but previously ran well. The problem remains when all these are powered down: Quadra660AV, classic networking, sys 7.5.x running LaserWriter Bridge for an HP4MP printer, a Quadra 475, Asante LocalTalk adapter for a StylewriterII with LocalTalk card (don't ask...)