Need to find out what processes are still attached to your database, thereby preventing you from restoring it?
Use SQL Server Managment Studio and check the Activity Monitor under the Management folder. You'll get a nice list of all the oddball processes you've got which are hanging on to your db. Right-click on the leeches and kill 'em off to get your DB in a state where you can restor it to.
(Uh, of course, make sure those procs aren't anything overly important first...)