Not sure about the version number thing (overwriting works fine), but it's obviously having difficulty yEnc decoding those files, the same 2 parts over and over ... failing crc checks, which means either corrupt files, bad memory or I/O problems. Have you tried with firewall disabled and/or NNTP scanning disabled?
Btw I tested those files, and they're fine here, in the log I see:
[21/09/2009 19:35:31] [Dec] Yenc file OCEANS_THIRTEEN_720P_X264_NLSUBBED_JUST4FUN_TEAM.part001.rar decoded in 3250ms