Me, too!! In fact, I was going to write nearly the same post as yours, so, although I can't suggest a fix, I CAN reassure you that you're not alone. I've had my 3800 for a few months, but printed only a very few times, and none at all for many weeks -- so forgot about the "problem" until recently when I jumped in again.
I find that the PS driver asks for a paper path in the "page setup" section (have you seen that?), but where I'm running into the glitch is when printing with ImagePrint. Can't find any paper-path options there . . .
Hope we both can get some help here!
--Ron