I have exactly the same issue (posted on a previous page), cgminer freezes on middlecoin only, both on BAMT and Win7. My suspicion is that due to frequent switches/disconnects cgminer is more prone to issues and is ready to go over the edge at any time. I've installed the latest ATI drivers on my BAMT box last night and it didn't freeze when a cgminer on my Win7 box did (11:35 PM PST), but showed a huge drop of kh/s at that point in time.
What version of cgminer are you running?
3.7.2 on both boxes. Tried 3.5.0 on my Win7 box, same issue, freezes overnight.
Like I said earlier, sounds like heat, hardware or driver issues. This would be happening to many others if it was a pool problem
I run win 7, with cgminer 3.7.2 and have never seen an issue like this.
it is possible something the pool is doing is causing YOUR computer to screw itself up and lockup, but the pool itself is not doing anything different. if this was a pool issue, it would be happening to many more people than 1 or 2