I just posted the same issues last night. Exact same things happening to me as well.

AMD Phenom II X4 955 black
16GB DDR3
Nvidia GTX 650 TI 2GB
Win 7 64
Nothing overclocked

Using WinEQ launcher or just a shortcut ends up doing the same thing intermittently with both.

well we've got similar processors... maybe we're on to something!

AMD Phenom II X4 B50 3.2ghz
8gb DDR3
Radeon HD 4850
win 7 64 bit
4th core unlocked on a x3 processor(always been that way for 2 years of playing now)

CPU: Intel Core i7-3930K 3.2GHz 6-Core (OC'ed 4.2GHz)
Motherboard: Asus Sabertooth X79 ATX LGA2011
Memory: G.Skill Ripjaws Z Series 32GB (4 x 8GB) DDR3-1600
Storage: Samsung 840 Pro Series 512GB 2.5" SSD
Video Card: MSI GeForce GTX 680 2GB (factory OC)
Sound Card: Asus Xonar DG 24-bit 96 KHz
Operating System: Microsoft Windows 7 Professional

AMD processors don't seem to be the culprit, as I'm Intel. Surely more than just a handful of us are having these problems.

What about ISPs?

I'm Comcast, in Tennessee.

I'm in the exact same boat.

AMD A8-3850 APU
4 GB Ram
750 GB HD
Windows 7 Ultimate (x64)
Comcast is my ISP in California

Comcast in central Pennsylvania

The things we're experiencing definitely seem like network issues... and Comcast is suddenly looking like a possible culprit. Although the timing of it all seems to coincide with the server getting the XP boost. I wonder if it's something on the server's side of things.

This is happening to me pretty much exactly as described, one two different computers. I also have the underfoot client installed on one of my computers, for playing on another server, and I don't apply the p99 patches to those files. Even my underfoot installation is having issues with the server select screen appearing blank very often. Not seeing crashing as often on underfoot, but on p99 crashing is very common since last patch.

Comcast in CA here too.

Jealous at your pings, us here in Aussieland get 300ms+ !

Also getting the same thing infrequently happening with the crashing whilst zoning.