Actually this version is:
Xtreme firmware 4.2A/B Rev.1 = ERROR 66 only
It's a new version of 4.2A/B, so if you don't have the ERROR 66 problem get the "old" 4.2A/B that was release a couple/weeks ago. The 4.2A/B is a good update. It's based on MS new FirmWare MS28, the old ones is MS25.
#4060