I have had top position for several months on some competitive adult
keywords.  My site is relevant and content rich.

My question is somewhat complex and probably will need revision but here goes:

Recently a spammer has seen it fit to start 302 redirecting to my
domain from various domains of his.  After google indexes his site my
index page is totally dumped from google (All other pages on my domain
are still found in google).  He then is redirecting the page back to
another of his domains.  I have done some research myself and found
that google has trouble handling 302 redirects and if you need to...
It should be a 301 redirect.

This is causing a huge problem considering the majority of my traffic
comes from google.  Is there anyway that I can somehow stop this from
happening so that google will stop dumping my index page.

Well, all I can think of is to deny all requests from his domains. It
may even be possible to deny all requests under 302 redirects (not
exactly sure how at the moment, if I think of it, I'll answer your
question with it).
It's an interesting challenge, to say the least.

Hey Passive.

I thought about what you're saying.  Doing it by domain would be
impossible since this person has 100's of domains and probably 100's
more.  Denying all 302's is definately a challenge can't find any info
regarding the topic.

If you're running Apache, you can redirect 302 errors in the .htaccess
file.  You probably have something similar setup for 404's or 401's...

ErrorDocument 302 /302.html

http://httpd.apache.org/docs/mod/core.html#errordocument

I don't know how common 302's are in normal surfing, so you may wanna
test it out and keep an eye on your logs.