It looks like the domain had three eras. It was parked for a while, then it was taken over by domainauctionhouse.com, and now you guys.

http://web.archive.org/web/20040601000000*/http://tripexpert...

The domainauctionhouse page had a link to domains for sale, which had an Adult section. Maybe the links to domains with bad words in them caused it to end up on filters.

http://web.archive.org/web/20050205024618/http://www.domaina...