Windows 7 Ultimate
SQL Server 2008 Standard
ColdFusion 9 Developer Edition
ColdFusion Builder Plug-In 220.127.116.111911 (I was part of the pre-beta and beta and it worked there with Windows Vista Ultimate)
Version: 3.5.2 Build id: M20100211-1343
Build id: M20100211-1343
Not sure if this would help, but try to apply CFB update 1 ( "Help > Adobe ColdFusion Builder Updates..." ). Then start eclipse with the "-clean" option. Also, do you have the CF server setup in CFB and is it running?
If none of that helps, perhaps try to create a new workspace ("File > Switch Workspace > Other"), that sometimes fixes oddities.