I have a 2001 Sport Trac with ~ 80k mi. Every time I start the engine when it's cold, the "check gauge" light comes on because the oil pressure gauge indicates no pressure. This has been going on for a while, and at first I checked the oil to make sure the level was OK, and it was. Within 5 minutes of starting the engine, the temperature gauge comes up to about half the normal point, then the oil pressure gauge springs up to normal...the idiot light also goes off.
I was wondering if anyone else has had this problem, and if so what they did to fix it.

I had the same problem on my 99 v-8. If I remember correctly, they replaced the oil pressure sending unit under warranty. It is a known issue, and if you do a little research or talk to your dealer they should be able to give you the info on it.
Sorry I am a little hazy on the details, it was a while back.

I think there is a t.s.b. on this as well. It would describe the problem and resolution.