AMD issued a patch today that effected its Opteron & Athlon 64 processors. The problem was BIOS related which caused these the processors mentioned above to freeze up.
Advanced Micro Devices has issued a fix for a glitch that could cause computers containing its Opteron and Athlon 64 processors to freeze. The glitch, dubbed "erratum 109," results from incorrect assembly instructions issued inside the processors, but is considered to be rare. It has only been seen inside AMDs validation laboratory, which uses specially-designed diagnostic software to test AMD processors, a company representative said.
AMD notified its partners of the erratum in April and recently issued a software fix for it to makers of BIOS system software, which helps run PCs and servers. Resultant BIOS software updates are likely to become available soon. Errata are fairly common in the complex business of manufacturing processors and are often dealt with through new versions of BIOS software. Those updates are typically distributed by computer manufacturers.
News source: C|Net News.com