The tone reference page should clarify how PWM functionality is affected when the tone function is used, for example:
On boards other than the Mega, analogWrite() (PWM) functionality on pins 3 and 11 is disabled after the tone function is used
On the Mega board ? (insert statement here)
Good point. I added a vague clarification, since I'm not sure of the exact behavior.
Have you tried it? Does it actually disable PWM or just mess with it? And does the PWM start working again when the tone ends?
according to this thread it does not start working again:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1265974637
Looking at the code, it does appear to turn off PWM with no way to turn it back on again.
it would be handy if the wiring init code was modularized so that functions like tone could re-init specific resources by calling the same function(s) used when the system starts up.
Yep.
That probably falls under this: Google Code Archive - Long-term storage for Google Code Project Hosting.