Created attachment 104370 [details]
Stack trace of Netbeans capturing the deadlock
Platform: CentOS 5.5 with latest patches as of time of writing, running inside VMware ESXi 4.1
JDK: Sun 1.6.0_23 (latest as of time of writing)
Netbeans: 6.9.1 with latest patches (201011082200)
Encountered 2 deadlocks (between "Property Sheet" and "AWT-EventQueue-1") while using the GUI editor, both times appeared to be triggered by the selection of a dialog component. These problems were encountered soon after the application of the latest Netbeans patches, and weren't seen previously.
Stack trace: see attachment
The same happened to me in 7.0beta when opening a form, attaching threaddump...
Created attachment 105292 [details]
FTD showing the deadlock after opening a form in 7.0beta
The first reported deadlock is bug 190774, already fixed.
The second report is bug 187697 appearing on JDK6 u21 and u22.
*** This bug has been marked as a duplicate of bug 190774 ***