Xcode 4.2.1 bootstrap / debugger error

[Perigee]

Does anyone know how to resolve this other than a complete reboot? I'm restarting both my work desktop and personal laptop on an almost daily basis, which is irritating, to put it politely:

Couldn't register com.your.App with the bootstrap server. Error: unknown error code.
This generally means that another instance of this process was already running or is hung in the debugger.

Thanks,

Matt