Hi Smithjohn,
First of all, run your domain name through this bad neighborhood free online utility:
http://www.bad-neighborhood.com/text-link-tool.htm
it will run all through your site and tell you ALOT about every site that you have outbound links going to and it could help you learn more about your current issue and maybe help you solve it, but please don't quote me on that. Also, you can read more about this free online utility here:
A Quick Clarification on the Bad Neighborhood Detector
Also, this takes some time, but it is a very good idea to check ALL of your outbound linked sites' current Big G status with this free tool:
Google Banned Checker
Most likely, this will not happen, but if you discover that you are, in fact, linked to a site that has been banned by Big G, then remove that outbound link ASAP!!! Then run your own domain through the above Google Banned Checker to be sure.
Good luck!
Rob