Exception thrown in a lock c#2

I've a strance behaviour with C#2, an exception is thrown will calling a lock(...). I have the following exception : System.Threading.ThreadAbortException: Thread was being aborted. at System.Threading.Monitor.Enter(Object obj)...

Have you seen that kind of exception ? TIA

This exception is being thrown because your thread is being aborted.

Threads can be aborted in one of several situations: another thread calls Thread.Abort, an AppDomain is being unloaded, or an ASP.NET application is being recycled.