Radio Volume Delay

[tachy]

I have a new gs 300, 2006, and notice sometimes when I turn the car on, and the radio was on, if the volume was fairly loud when I turned the car off, it seems to take a fair amount of time before the volume knob will enable me to adjust the volume.

I have tried to get in the habit therefore of turning down the volume before I turn off the engine. (but occasionally forget) I have never had this problem before on prior cars, since the volume knob usually seems to be responsive without delay.