Longstanding bug on windows for when network goes down; it's my secret way to get people to move to linux.
Obviously not the case, but anyway I've not been able to reproduce it myself so must be some combination of windows or other issue. You could always try helping debug it following instructions in here:
http://ck.kolivas.org/apps/cgminer/debug/I suspect it's just the libcurl implementation on windows... which would be bad news since it won't be something I can personally fix.

between linux and mac users, the jabs never end...
Will do on the debug.... I may be working in an uncommon setup which may be compounding the issue. I run plonk to create an ssh tunnel on port 3333 to the pool via my home DDWRT router. Because the SSH tunnel can collapse at the slightest of network hiccups, which we have many, I restart plonk every 30 minutes. I believe the issue only happens when connected via stratum protocols. Too early to tell, I just started with cgminer since my pool switched over to stratum. However, I wish I had looked at it sooner because I am getting much better hash rates with cgminer!
Thanks!!