The usual problem is a loose cover at the back of the headlight, either the large plastic one or the smaller round rubber one.
I seem to recall (not 100% certain) that they may have had a bad batch of plastic covers. What year is this truck, and can you tell me the last 6 digits of the VIN number, I'll try to check and see if your truck may need new covers.
Make sure they are correctly installed though for sure.
Gilly
ps, Tabo:
knock off with calling the original headlights ugly. They look fine. The newer ones look nicer, but the old ones aren't ugly.