jruby / tomcat thread hung

All,

 Still experiencing weird problems where 1 of my 4 processors intermittently hits 100% cpu and tomcat completely locks up my rails app and no future requests can come in, even with spare CPU cycles.  Can anyone help diagnose what process is preventing JRuby from handling any requests?  I have a copy of the kill -3 here

http://pastie.org/237926

 Seems there are a lot of WAITING but not sure where to track this down to, or if anyone has any suggestions on how to get better granularity on the threads that are locking everythign up.
 
 I do notice this but not sure hwo to track down this thread:

   - waiting on <0x00002aaac1d37b88> (a java.lang.ref.ReferenceQueue$Lock)
        at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:116)

 Thanks
 Adam