Possible MIDI Bug?

Running X1b with hot fix and quick fix on 64-bit Creation Station with V-Studio 700.  Three MIDI modules connected via M-Audio MIDISport (4x4) and an Akai LPK mini-keyobard connected via USB (for quick input of simple parts).  Plug-in VIs from Vienna, Synthogy, and EastWest
 
Sometimes all MIDI I/O dies.  Nothing responds to MIDI messages and Sonar does not receive any input from any sources (even though the devices are still checked in the Preferences).  Solution is to reboot the PC and restart Sonar.
 
This also happened when running a MOTU Microlite 5x5 instead of the M-Audio.  In fact, I originally thought the MOTU was defective.  Since the USB keyboard also dies, the problem is likely not the MIDI interface.
 
I can fix this with a rebot but that is obviously a pain.  Anyone experience this?  Is there are fix—or maybe something I am doing wrong?  (Sorry, I can't really document the steps leading up to this as it seems a bit random.)
 
Thanks, Konrad

konrad, you know the midi icon in the task bar next to the clock, does that even respond also ?

how is your USB wired up via a hub or anything and there is enough power going to that device ?

have a look under system devices to see if it's sharing IRQ's.. that might point to an issue also.

I use a Cakewalk UM-3G in 64 bit without issue (you can chain up to 3 of them) for my midi xg module. I'm not a fan of m-audio now and won't be buying any more, even though I own 5 of their products , their drivers are not on point for products I have, even AFTER they "supposedly" updated them , the same bugs.

I would try contacting support also, maybe there is a crash log somewhere to access.  It's slightly easier for me to fault find as I use different music things, so that helps me pinpoint things due to how different things are implemented in.