Sometimes knobs, and on-off/slider switches just need to be cycled every now and again. Perhaps that is what it needed. If not, it would be interesting to know if there is an error code associated with the malfunction. It might be worth getting it checked next time you take your 'rolla in for an oil change (if you take it to your dealer, that is).
The dealer has ordered a new radio (stereo) for me, no hassle at all. They've had other Corolla's in for the same problem. Apparently its a known issue.
The car was in for the brake assist re-call so I don't know if they read the codes off the computer for the stereo not.
I do my own oil changes, the dealer charges $39.99 plus tax, if your vehicle gets a grease job its an extra $16.95.
There is a recall on the brake assist? Oh, you're talking about the manifold thing. Gotcha.
By the way, do you know if there is a Toyota Service Bulletin (TSB) on the radio? Thanks much if you can tell me.