1990 Civic sedan - shift lock sticks when cold

I have a 1990 Civic LX with automatic. When the car is cold (during winter, like now), the shifter/brake safety interlock will stick so that I can't get the key out of the ignition. Pushing the shifter handle hard to the top of P and waiting will generally free it, but sometimes it takes several minutes. This is very temperature dependent--not a problem when it's warm, many minutes when cold.

Any suggestion on what this is or how to fix it?

Thanks,
dex

When you put it into park, does the park light some on? Or do you have to wait for it to come on as well.

No, the parking light doesn't come on either. When the light comes on I can get the key out.

I think the solution is here: http://www.askmehelpdesk.com/cars-trucks/honda-civic-not-shifting-out-park-key-stuck-55351.html

Haven't done the work yet but I feel like this is probably it. Thanks!