I wouldn't reinstall PT10 just yet. (It's a huge pain and should only be undertaken when all else fails). Besides, the 'busses' and I/O pertain to the ASIO/firewire channels; USB has nothing to do with that.
As I mentioned earlier, I experience the same issue when PT10 (and even its predecessor PT9 as well as my long-gone Cubase). It only happens when the DAW is resident; at all other times, TMC is available.
TMC runs by default on its proprietary USB1 port. It MIGHT be that your DM's MIDI settings are somehow interfering with USB1. The way to check that is to go to your DM's MIDI page, and study the 'flowchart.' (I call it the 'plumbing schematic.') Trace the in/outs to/from USB1. You'll see 'TMC' at the upper right, and where it connects in the scheme. If you discover something also connected to USB1 (unlikely), disable that connection by cursoring over it and hitting ENTER.
More likely: you PC/Operating System is 'hijackin' USB1 for some other purpose. Check in the Devices/USB menu - going into the 'Advanced' settings to see what USB ports are assigned and where.
Short of that, I have no other suggestions; I've simply used TMC before or after running ProTools. TMC just isn't available otherwise, and I've yet to find out why.
CaptDan