Pentax 80-320mm in strange condition

Hi all!

I have just received my Pentax 80-320mm 4.5/5.6 that I bought of eBay, but it arrived in a very strange state.

It has two visible problems: the first one is that the zoom ring is very loose from 80 to 100mm and then tightens up immediatly and immensely to a point I almost cannot twist it with one hand only... but it does twist, and work.

Then my biggest problem; although the lens is in "A" mode, neither my *ist-DS nor my MZ-50 acknowledge it. They seem to think the lens is in a non-A position, and display "Av----", just as they do with my Pentax-M 50mm F/1.4, not controling the aperture.

The focus ring doesn't feel smooth as well (seems like it has small grains inside), but this lens is old and has been used (and probably improperly stored). Is there something I can do for it? If I can't/shouldn't do anything myself, where can I send the lens for repair/cleanup an how much would it cost me?

Thanks a million!
--
Oscar

I've been shooting a bit in aperture priority (wide open) and manual modes with the lens; it really is a very nice telephoto on the DS, producing great results even under very difficult conditions. Flare is well controlled as well.

Even the Pentax SMC-FA 35-80 F/4-5.6 that came with it surprised me in terms of quality!

But the fact that my 80-320's zoom ring is sooooooo tight really puzzles me; I've read everywhere (in Stan's site as well) that the zoom ring is very LOOSE... mostly everyone complains about the lens zoom creeping when held/placed in a vertical position.


Does any of you confirm this loose zoom ring on your 80-320?

Thanks!