Ever increasing Background tasks on OSX

Using latest IDEA 11.x with latest OS X 10.7.x

The problem started to occur since the migration from IDAE 10.x and is occuring with latest release.

The amount of background tasks seem to increase for ever and no task gets ever done.

please see attached pic for an exemple.

I'm doing a lot of Search & Replace, and background tasks seem to reflect these past - successful - searches, even though I got a result for them.

thanks