Radio

When i start the car after it's been standing for a while the radio comes on when the ignition is turned on but then goes off.

I can get the radio back on after a bit off messing round with turning the engine off then restarting it.

Any one got any thoughts why it's doing it?

it has only recently been doing it! :/

Also Ive got a very small leak on the door seal by the front passenger door. Any one got any ideas on if it's an easy fix??