Radio goes silent

So I'm driving along in my 2001 9-3 hatchback and periodically the radio goes silent. The SID then only displays the time and temperature, the dial number of the radio station vanishes. I then turn the radio off and when I turn it back on, it plays but the SID still doesn't display the dial number of the station. If I stop, turn the car off and restart, all is well. Is this a SID problem or a radio problem or something else? Thanks.