DigiUSB turns the timer interrupt off, it also messes with interrupts on each send and receive - in addition the rc-switch probably makes extensive use of timer which may be on different ports with the Digispark - but if it compiles maybe not... so then it is just a timer issue - no generic way to resolve it, eventually I\'d like to evolve the DigiUSB library to allow you to use other timer dependent things with it, but that might be few weeks yet if someone else doesn\'t do it first.