My suggestion would be to try to include everything in your UC setup as possible.
I would imagine that if you were to use UC to completely shut of the radio as the first task or line item in your UC script, then this will probably work with 100% reliability.
Code:
EXEC:\Internal Storage\RadioControl.exe -radiooff
<insert lots of UC stuff here>
EXEC:\Internal Storage\RadioControl.exe -radioon
I don't recall the kind soul who developed the radio control application.
Best regards,
-boggsie