Today I encountered the problem that every time I started one of my Eclipse workspaces it always started to build the workplace and could not finish it. The progress monitor showed additional tasks waiting but I could not stop them. After killing the Java VM process several times and starting up again I searched for a solution and found this page.

I already heard about the clean command line argument and after adding it to the command line it resolved my problem. I will not add this permanently to my Eclipse links because it takes significantly longer to start up but I did a good job to fix the workspace.