After some prodding, here is what EpoX officially states on this problem. Larry
Thanks for your concern. We in fact have tested 550 in the past and they did pass our basic internal testing when they were first released. Many users already have had success with the combination. But for users purchasing recent boards and CPUs that experience stability issues such as the ones you mention - I do not know if the AMD processor have changed as the motherboards have not had any significant changes for quite some time. For safety the bulletin you referred to will show 500 as the max right now. But for users that already have the combination I would suggest the following:
AMD recommended thermal FAN/heatsink
Additionally to help with the stability issue changing the working Vcore
voltage to +/- 0.1v may be helpful.
If issues are present when first installing Windows try to disable UDMA mode
for all the IDE channels. After setup is finished install all necessary VIA
drivers, video, etc. Then re-enable UDMA mode.
Ensure the processors are not AMD K6-2+. Only K6-2 are supported.
Further ensure the users have flashed the latest released or beta BIOS for the board. Find attached the latest BETA. Released version can be downloaded from our site.