Compatibility issue with pre-EOS lenses and EOS bodies?

Hi,
I really hate to start another thread on the 70-200 F4, but I just finished reading another thread on the need for Canon service to correct focus problems on a new lens.
I'm definitely interested in this lens for a 20D, but I keep seeing threads on focus problems.
This and the 17-40L.
A very knowledgeable Calumet salesman recommended strongly that I not try to use a 17-40L with a 20D.
Is there some kind of compatibility issue with pre-EOS lenses and EOS bodies, or is Canon quality really that spotty?
Anyone have an opinion about the percentage of bad 70-200 F4Ls coming out of Canon?
Thanks
Pinto

Pinto:
I'm not sure what you're really asking here because pre-EOS lens compatability really has nothing to do with Canon quality.

Lenses prior to the EOS system were mostly FD mount. They are not compatable with EOS bodies by design. There are adapters that allow you to fit an FD lens to an EOS body, but there are inherent problems with them...you will lose a lot of the automatic functionality of the newer lenses, and will have other problems, such as focusing to infinity and having to step down aperture manually.

Again, I'm not sure what this has to do with 'spotty' quality.

I took a couple hundred shots last weekend with a 17-40L lens on a 20D. It worked perfectly, and I think your Calumet buddy might be full of soupl

Thank you for your response.

I'm sorry, but the post should have correctly questioned the compatibility between EF-S Bodies with prior EF-S lenses, not EOS and prior EOS.

From the large number of posts on problems with EF lenses on EF-S bodies I think it raises a legitimate question.

I'm glad you have a good copy of the 17-40L, but why is there a need to "recalibrate" all these lenses if there isn't some issue with quality?

I'm just trying to learn.

Thanks,

Pinto