Cheers guys, I changed a couple of cvar values specifically around the "WARNING: bad command byte for client XX" to which clients where having to reconnect to remove issue.
I deleted my old .pk3's like Mini suggested, haven't had any problems since the reversion. Put my maximum fps to 90 today, and use a new laptop. Stable as never before. I can even watch at smoke again. Wow. J enjoys ET again!