would be interesting if there were a way to lock the screensaver, so that seti would run whenever the comps weren't in use...
of course compiling they're probably left alone so it would kick in then, i assume thats what you mean by heavy duty (since coding takes zero processor time)
the seti server dying can get around by using setiq on one comp (perhaps your workstation?) and just caching, then the other machines wouldn't ever have a problem with that. they won't ping the servers constantly. the clients will retry every hour, so at worst its every 2 minutes the server gets pinged. i haven't personally experienced instability traceable to the seti client (though that nvidia driver still isn't perfect, much better than it used to be), and it doesn't seem to slow down processing of other applications. i think with one of the monitoring programs its possible to set the client's priority even lower. and if you can get it to work as a service and tell windows to optimize for desktop applications that should help it. sukhoi has some service disks posted to his page, but i think hes on retreat somewhere.
EDIT: if you do a search for service, message posted by sukhoi, you'll find the link to the disks