I see that there was a jira INSP-1418 for an IllegalMonitorStateException on line 244 of loader/file/FileCacheStore.java

I'm getting a similar, if not exactly the same, exception about 30 seconds after Infinispan fires up within my TorqueBox 2.x build 504 app server.  
https://gist.github.com/1272662

This particular Sinatra app is here:
https://github.com/lance/beer

TB 2.x build 504 is using Infinispan 5.1.0 Alpha.   Substituting in 5.1.0 Beta had no effect.

Thanks!
--penumbra