Created attachment 118998 [details]
Just after startup, I had several JSP files open. In one of them, I Ctrl-clicked on a reference to another JSP file. After a while, dialogue "Lengty operation in progress" appeared, with text "Go to Source" (scanning of projects was not finished yet). The progress of the Scanning projects task stopped, i.e. the task did not continue (0% CPU usage) and the dialogue "Lengthy operation..." never disappeared. I tried to cancel the operation by clicking the Cancel button in the dialogue but NetBeans did not react.
After a while, I used JVisualVM to generate a thread-dump - see the attachment.
Windows 7 64-bit
JDK 6u32 64-bit
quad-core Intel CPU