I've been having the same issue as Angle for about a week now. Every time I log into Second Life, it stays connected for roughly 1 or 2 minutes, then disconnects me with a message saying "Darn. You have been logged out of Second Life. The region may be experiencing trouble. Please check your connection to the internet." I've tried logging into more than one region and it still does this. I've tried using different SL viewers and it still does this. My wife experiences the same problem on her computer with her avatar.
To answer the questions yo posed to Angle:
You're not using wireless, are you? No, I am directly connected via cable modem on my laptop. No wifi being used.
And here is the info copied from my regular SL viewer and pasted here:
Second Life 3.6.1 (278007) Jun 27 2013 12:41:07 (Second Life Release)
Release Notes
CPU: Intel® Core i7-2630QM CPU @ 2.00GHz (1995.53 MHz)
Memory: 8170 MB
OS Version: Microsoft Windows 7 64-bit Service Pack 1 (Build 7601)
Graphics Card Vendor: NVIDIA Corporation
Graphics Card: GeForce GTX 560M/PCIe/SSE2
Windows Graphics Driver Version: 9.18.0013.1422
OpenGL Version: 4.2.0
libcurl Version: libcurl/7.21.1 OpenSSL/0.9.8q zlib/1.2.5 c-ares/1.7.1
J2C Decoder Version: KDU v7.0
Audio Driver Version: FMOD Ex 4.44.12
Qt Webkit Version: 4.7.1 (version number hard-coded)
Voice Server Version: Not Connected
Built with MSVC version 1600