I just performed an experiment here, with my 2010.5 build 303 BiaB.

Changed to "Use DXi" with the VSC DXi synth.

ASIO drivers were already invoked, with "ASIO Always On" checked.

"Route MIDI Thru..." UNchecked.

When I closed the window, I could see the onscreen keyboard highlight notes played on my MIDI Controller Keyboard, but could not hear them.

Pressed Play and let the song load, then hit Stop.

I could now hear the keyboard playing trhough the VSC DXi.

Tried closing and reopening BiaB, the Controller Keyboard would Immediately allow playing on the Thru channel as soon as BiaB was done opening.

Rebooted the computer (yeah, long wait, but...) and reopened BiaB, after it settled down I could again play the MIDi keyboard thru the DXi synth immediately.

Somtehing's going on if you cna't hear that thing, but I'm not sure what it could be at this point...


--Mac