Please remember guys that MAME (kaillera builds) handle kaillera netplay different than FBA because those build are specifically modified to work good while playing online. FBA has support for Kaillera but afaik FBA was not specifically made for netplaying.
I can't say that issue with SFIII3N is related to the CPS3 driver because I think a driver can't modify or affect the kaillera external (DLL) core.
To be sure that there is a problem with the CPS3 driver and netplay we have to make testings with a excellent internet connection, an excellent kaillera server, an excellent video card, lot of RAM, no firewalls and lot of other things ...and then if the problem persist we can blame the driver and FBA.
I don't have a extreme internet connection to be developing FBA in the netplay aspect, but maybe in the future if I have the resources I will try and work on the support of a better netplaying for FBA.
SeeYaa!