Webwork - 1:28 am on Jun 18, 2012 (gmt 0)
Quite a bit depends on facts that, in the absence of, it's very hard to offer guidance BUT, in the presence of (posting those facts here, in your thread) you could be putting a bullseye on your forehead for the purpose of future litigation that might wipe you out financially.
The most worthwhile advice we can offer you is "talk to an IP lawyer", which will probably cost more than the domain name is worth to you, which is probably why you're seeking our otherwise feckless assistance.
Sorry. We labor to be feckful, but in the case of legal opinions less seems to be our lot in life. Failing all else we hope our presentation of non-advice will at least cause some to smack their heads, chortle and confess to themselves "What was I thinking?!" :-/