Connection drops, LL tech support claims "resolved"

At random intervals, my connection to SL drops. Sometimes it's minutes, sometimes it's hours, SL randomly stops responding and then soon tells me I've lose my connection. While this happens, my connection to the Internet is fine. Other progams, including SLVoice.exe, remain connected without issue.

Further mystery- sometimes I run two accounts side by side. One computer, two monitors, two accounts logged in. Half the time, only one of the two accounts gets disconnected, the other continues to run without an issue!

In attempts to fix this, I've tried different viewers, cleared cache, replaced my modem, replaced my router.

I've called my ISP to ask if they're aware of issues. They say no.

Bump

A questionn. You say while running two clients side by side from the same computer one will drop the connection while the other does not. I'm wondering when this happens what client is active when that connection gets lost? My thinking is that it's probably the client that is NOT active that gets booted while the client you are actually using remains connected. I'm not sure what that would tell you except it's a focus problem of some kind. It might help or spur some ideas on where to go next if you can pin something down that narrows the apparent randomness.