I had this problem using poclbm on one of my 5850s, would run for a while and then crash, and then i'd reboot the whole machine. This got old really quick and I searched for a way to get past these errors. sure a script could be written to solve it sure. But I switched to Phoenix 1.50 and using the phatk kernels the problem has gone away, the error handling in phoenix seemed better than poclbm. Where as a verification failed halted the miner, phoenix will automatically reissue new work and keep mining away so even if I get ahardware verification failed which in phoenix is something like opencl internel error or something of that nature. Try using phoenix and see if that doesn't solve your problems of constantly having to restart the card. I was also running 3 cards in once case when this started to occur.