My FIRST pair had little rust spots on them after 2,300 miles, so i called jegs and they let me exchange them because it was still under 1 year. I now have my second pair and they have done the same exact thing. I decided that it's not worth the hassle to take them off and send them in. I am very dissapointed, you pay extra for the Jet-hot and this crap happens.
Particularly interesting as the FRPP headers are stainless steel.....I had my FRPP shorties ceramic coated locally by a small shop that does that. Over 2 years and about 10K miles on them -- they've lost a bit of gloss (actually I'm glad they did - I HATE chrome/polished stuff on my car), but other than that they're holding up brilliantly.
My MAC equal length shorties rusted like Nick said above, and my BBK LTs are doing the same thing. Personally it annoys me but not too much since I bought the headers for performance instead of looks. I also realize that constant heating and cooling of metal, especially if in a more humid climate will cause rust.
Tim
Tim