Library state is jumping

Hello guys,

I'm new in this forum and hope you can help me with my problem.

I've problems with a library in BE 2010 R3 running at Win 2008 r2 x64.
The state of the library is flapping very fast to "In use" and back. Funny thing is that there are no jobs (e.g. Backup, Inventory,...) that might use the library.

I've already restartet the BE services but this doesn't resolved my problem.

BR, Florian