Shift lock problem

Can anyone help on this please?

I am getting a problem with the shift lock not releasing when the brake pedal is pressed. It seems to work fine once you have got it out of Park in the first place. Then, when the engine is switched off and started again, same problem!

When checking it after releasing the first time, the solenoids in the dash can be heard clicking merrily away. But not after the car has stood for a while.

Taking me longer each time to make it work, usually by moving the lever to and fro and swearing a lot!

Thanks in anticipation