If you are using Oracle VM Server it is possible that you are hitting the following problem:
After changing something on a server pool the pool gets locked and the lock stays there:
The solution can be very easy:
Just edit the pool and add (or change) the description.
This edit triggers an update and removes the lock. I think every other change would do the job, but this is a minimal change, which solves the problem...
Hopefully there will be an update, so this problem will disappear in future versions.