After upgrading to Infinispan 5.3.0-final I found a strange "intermittent" problem in my application. Digging a bit deeper, I found out it is due to CacheEntry events raised twice for some keys on the local node (the node where the cache operation is invoked).
I was able to reproduce the problem and I wrote the attached test case.
The problem happens regardless of the cluster mode, but only with non-transactional caches. I think this is due to the fact that with transactional caches the events are raised on commit.
Also, my application used to work with an interceptor rather than an event listener, so I actually found the problem when I saw my interceptor being occasionally executed 3 times with 2 nodes.
I'm not sure whether the command and the chain of interceptor is really meant to be executed twice on the local node, but the consequent behaviour on the events sounds like a bug.