Server hangs without error messages

[Hathor]

I'm running the current ServUO server using a 7.0.31.0 client. Startup is fine, I can log on, bracket commands execute normally, chars can move around and do things. The server locks up after announcing "High Tide Enabled", chars freeze but can still use the button on the paperdoll to log off, if you try to log back in, the client hangs on "Verifying Account", and the server window won't take commands.

Has anyone else seen this problem, and is there a known fix?

 

[Hathor]

OK, cut the expansion setting back to ML, and attached it to one of our old 7.0.12.1 mul-map clients. Everything works fine. Again, any ideas on why the 7.0.31.0 set to SA would be having trouble with Z settings (NPC's spawning at -85, etc.), and High Tide would cause trouble?