Well, the least I can say is that my D80 with Hoya circular pol behaves quite normal: no need to correct WB or exposure. But I haven'T yet found the source that tells me, what the effect of linear pol-filters could be. So I'm not sure about it.
If you use "linear polarizer problems DSLR" @ Google, one of the top 10 entries goes to a test of a user that says: "Linear polariser & 20D: no problem! (quick test)". And someone else said that AF and exposure (on a Pentax) were ok with a linear pol-filter.
If linear is making troubles I'd expect the troubles to be dependent on the angle of adjustment (of the filter) on your D80. Have you tried this?
No I have not been very scientific about it so far - why is life such a rush? I never have the time to do anything properly any more!!