Created attachment 101442 [details]
...see attached jstack output.
If I could, I would set the priority to P0. It already happened 3 times today!!! It really makes progressing in my work difficult. I hope to see the issue fixed ASAP.
Known bug in 6.9; occurs when a pom.xml file (which you have opened in the NB editor) is modified by an external application (e.g. svn up).
*** This bug has been marked as a duplicate of bug 187615 ***