Library Cache: Mutex X events flood database

Hey,

we are observing some very high levels of library cache: mutex X event on our Oracle DB 11.2.0.1 (will be upgraded in the next few months unfortunately).

I checked that 99% of this events comes from one type that is created by ESRI Framework. So this is our hot object and we cannot duplicate it in library cachce until we got upgrade to 11.2.0.4, right.

But the weird thing is that 95% of time DB works quite well, and then it happens - library cache mutex X floods db and almost everything stops that people cannot work with our System.

I was searching for any object or sql that causes that but i couldn't see that any sql(or object) had excessive usage. It looked like usual workload. Except that we got 100x more library cache mutex X events that caused heavy CPU usage and performance issue.