Count yourself lucky reaching 4 parts in USB mode. Mine goes crackle crazy with 3 parts, using only analogue outs + midi in (USB completely disconnected).
I eagerly await to hear Access response to my last email which included an mp3 highlighting the issues (even in solo mode with first 3 examples).
You can also listen to it here:
http://www.arksunmusic.com/music/virus_issues.mp3
I'm on the TI Keyboard and the part that is most frustrating is, knowing I have fellow trance producer friends with the Desktop version, that have been running almost perfectly! (yes using full on reverbs/delays/eqs/hypersaws) . Standalone and USB, multiple parts simultaneous. And yet mine goes into a spasm at the slightest hint of being pushed (and as you can tell on that mp3, its really not being pushed that hard, note stealing coming in way too easily)
It's almost like my virus is running on half a motorola chip, let alone two of em.
So quite why some machines with the 1.1beta are running fine and some aren't. Who knows.
A whole dodgy run of hardware?, a manufacturing defect on some machines?. The core hardware should be the same between the desktop and keyboard versions after all. Just doesn't make sense!
All speculation at this point of course until we hear an official word on this.
P.S. My TI Keyboard is 4 days old.