I have a very similar issue to this. I'm using 3 BCF2000 units on a machine with Win7 64 SP1 and a Fireface 800. All BCFs are connected via USB. The Fireface MIDI is unused, and I have an Maudio keystation 88 plugged in to this machine via USB. I'm using the Behringer drivers, but experienced the same with class compliant drivers.
The issue seems to be the BCFs change the way their names appear to Win7 (or Win7 renames the BCFs) from time to time.
Correctly enumerated, the BCFs should appear like this:
BCF2000
2- BCF2000
3- BCF2000
but will unpredictably appear as:
BCF2000
2- BCF2000?
3- BCF2000
(the question mark above can also be a ` symbol)
Alternately, one or more units just won't be there, and the USB light will be off on the corresponding BCF(s).
When this happens, the Behringer virtual LCDs and the DAW I'm using (Sonar 8.5 and PT10) will, of course be unable to find the control surface.
The fix for this seems to be rebooting the incorrectly enumerated device while Win7 is up and running, and BEFORE launching the DAW (or presumably TotalMix).
My way of working now is to:
1. Boot windows
2. launch one of the Virtual LCD strips, right click it to see if the entries are correct. If they are, launch DAW.
--if not--
3. close the Virtual LCD strip (important, as rebooting the BCF with the V-LCD open will crash the V-LCD)
4. reboot the offending BCF(s)
5. relaunch the V-LCD, recheck.
6. Repeat this until all listings are correct.
Unfortunately, moving from Sonar to PT requires a reboot of all the devices to change from MC-S to bhui modes. This typically will cause the above scenario, and usually requires multiple BCF reboots to solve. It's an absolute PITA, and I suspect the resolution is just to buy a multiple input MIDI to USB device and run the BCFs in MIDI mode (not sure if that works well or not--does anybody here successfully use BCFs this way?)