It still sounds like intermittent network connectivity.
Do any of the users complain about webpages sometimes failing, etc?
How about opening a command prompt and monitoring the internet connection for a while
by typing 'ping -t yahoo.com'
or 'ping -t (serverIP)'
YOu shouldn't be getting any dropped packets on the local network. (pinging the server)
Check out this handy little utility:
http://downloads.zdnet.com/download.aspx?&kw=Ping-Probe&docid=251557
It will run pings to multiple locations, and record the statistics (dropped packets,
etc). Try letting it run a ping to the server for a day or two from a computer that
has acted up. If you see an excessively high dropped packets rate, then you might
have found your problem.
