Aviatrix,
We have no reason to believe that Flyertalk's database of user emails has been compromised, and we just finished a security sweep of the site's servers that would have notified us of any infected machines on the network.
It's also worth noting that the only time any outside party has access to user email addresses is for the newsletter. Even moderators can't see your email addresses. The only exception to this is when you use the "email user" function of the site. Whenever you contact member through the "email member" option, you are giving them your forum email address. (which is why there is a warning on that page that reads "Note: By using this form, your email address will become available to the user who you are emailing.")
Other than that, I can't think of how this address ended up out in the ether.