Transfer Case?

[Zortster99]

Well, I had a weird thing happen tonight on my way home... I was in 2HI driving on an icy surface. The back wheels spun a bit, but I was only going 10mph as I was pulling into a driveway. Now the strange part... once I pulled into the drive, it was VERY obvious that the truck was in 4HI, although I did not touch the 4WD switch, the switch was pointing to 2HI and the light was still lit on 2HI.
The front tires were binding everytime I made any turn on the dry concrete driveway, just like it should do (in 4WD mode). I've driven 4WD vehicles all of my life (25 years of driving) so I knew immediately what was going on by the way the truck rode and drove. Even the passenger in the truck knew (he's my dad....he knows everything :-) ).

If I take the truck to the dealer, will the computer tell them anything? No warning indicators lit on the dash. I tried putting it in 2HI, 2AUTO, 4HI, and 4LO but nothing unlocked the front tires until I drove in 2HI for about 1/8 mile.