OK, just talking to myself here, did a total uninstall of access and virus ti software etc, cleaned registry of traces of access and virus ti stuff. (I've had the same XP and virus ti combo for over 3 years )
Fresh installed 3.0.5 and got sample accurate timing, yay!
But lots of stuck notes and less polyphony, no joy.
Two tweaks later and back to normal...
The tweaks are:
Regedit - HKEY_CURRENT_USER\Software\Access Music\Virus TI\Virus Control
change ShowMIDIActivityMeters to 0 ( something to do with my graphics setup and dual view vertical monitors or what ever )
and
Lower RME buffer to 512 from 768
Each of these tweaks alone doesn't stop the stuck notes but together they are bliss.