In a remote desktop session users working from a mapped drive opening pdf, office docs and pics and it will randomly drop connection. It will return on its own eventually but its extremely random and happens very often. OS is Windows 2003 Enterprise. Why ? There are 9 people that use this particular folder and it doesn't happen with everyone just random.
Nothing in the event logs pretty clean actually. Some use thin clients other use desktops one not attached to the domain, other is. Server is no more then 20 feet from everyone, everyone goes thru a sonicwall TZ170 with a netgear switch in that mix. About it, pretty simple layout.
You can see it thru network neighborhood just fine even when the mapped drive isn't working.
Is the file server windows as well? Maybe check there are no dns issues on the domain, ie incorrectly resolving servername of the file server, or something part of the time.
Make sure all the clients are using the domain for dns.
Do you have anything graphed on the network, often just being able to look at a network graph will lend a clue to an issue. Install snmp on the filer and terminals.
I assume the internal network is all free to do what it likes, on the internal side of things, maybe check the rules over to make sure.