We recently moved our I-link database (3.3, M020) to a new server machine. For some reason OracleTNSListenerL816 service "terminates unexpectedly" once a week. Otherwise, Intralink runs fine after manually shutting down and restarting dataserver (and then it happens again after 7-10 days).
The IT department here apparently automatically reboots the Pro/I servers once a night to prevent unexpected occurance of something similar. They have done this for a while, probably since migrating from Unix servers. We are currently on 3.3 M021 and the servers are all Windows 2000 Server.
At my last job we ran all Sun servers and they would run continuously between upgrades and long-term power outages without being touched.
I'm sure our IT department would be interested in hearing other solutions you find.