As for web-based I was meaning that the local server would serve the actual "web page". So instead of installing AC on each network computer you would just browse to the host/IP of your main server and access it that way.
I'm the "outsourced" IT guy actually. I know more about networks and servers than I do about medical stuff, that's what my dad is for
I've done some pretty vast testing. At the time the nurses and scheduling folks get booted from AC I always have them try to browse a fresh web site. I will often times just have them go somewhere random, like viennabeef.com and so forth. The webpages always load up just fine and fast. At the same time I will RDP into the server and double check DNS requests, pings and traceroutes out to various sites on the Internet as well as to computers on the network. Everything checks out. The network computers get the "browse for database" screen when re-starting AC. They can browse to the network share, click the xml file and AC accepts it then tries to connect to the server, just to time out again. The only things that fix the issue is rebooting the server, restarting the SQL service or going into Amazing Utilities and hitting "Repair connections". After one of those actions is done then people are able to connect again.
Unfortunately I am a CCNA, not a DBA. My experience with SQL Server is fairly limited so it's a new animal to me. The tough thing is that we are stuck with Server 2008 standard, I can't downgrade to 2003 Standard due to funding. In some other threads you were toying around with upgrading 2005 Express to 2008 Express, have you beat that around any more? Does it seem to survive ok? I may give an upgrade to 2008 Express a shot.
I am currently having staff keep record of the date/time, error message if any and what they were doing at the time of an AC "crash" when it presents them with the "browse to database" screen. Hopefully I can compile that data at the end of this week to get a better idea of how often this is really happening. The Event Logs don't show anything so far that I've noticed that would indicate an issue with SQL Express, but who knows. We are using AC 5.0.28 currently.
