Deleting a project from the navigator pane doesn't delete the project from the location. If you physically go to the location you will see a .project and settings.xml which indicate that a project has been created on the folder.
If you wish to work on this project you can import this Project by Right-Click in Navigator Pane -> Import... -> ColdFusion -> Import Existing Project. In this wizard specify the location(in your case, ColdFusion8/wwwroot) and your project will be imported again.
Hope this helps.
DELETE should mean "it gets deleted". I can see how there might be grounds for there to be a UI option to not delete the files from disk, but given there isn't one, it's a bug that the files don't get removed, and accordingly subsequent attempts to create a project of the same name gives "unexpected results".
When I go to delete a project I see this dialog:
Checking the 'Delete project contents on disk' option causes the project to be removed from disk.
As already suggested if you don't check this box then you can either manually delete the project from disk (probably in C:\Documents and Settings\<username>\Adobe ColdFusion Builder workspace) or reimport the project.
To reimport, right click in the Navigator pane and choose Import. Then expand the ColdFusion folder and choose 'Import existing Projects'
I don't think it is an unexpected result that you cannot create a file of the same name in the same location as an existing one. That's just the way a file system works.
Yes you're quite right. I was thinking that was a reference to the source code within the project, not the project files themselves. My bad.