cgminer 2.5.0 and 2.6.0 (2.6.1 is not yet tried) occasionally hangs after showing "long poll detected new block".

My OS is win7 pro 64bit, and gpu is HD7970 oc to 1050/900. Mining at btcguild. Here is the command line:

c:\cgminer\cgminer --kernel diablo --auto-fan --gpu-engine 1050 --gpu-memclock 900 --gpu-memdiff -150 --temp-cutoff 90 --temp-hysteresis 1 --temp-overheat 84 --temp-target 78 --gpu-threads 1 --queue 1 -I 10 --retry-pause 1 --url mine2.btcguild.com:8332 --user user --pass pass --url mine3.btcguild.com:8332 --user user --pass pass --url mine1.btcguild.com:8332 --user user --pass pass

p.s. mine2.btcguild.com and mine3.btcguild.com has same ip address, will this be the cause?

Sorry, I missed the output line "GPU 0 stopped reporting fanspeed due to driver corruption"