Bridge slow to begin regenerating new thumnails after making adjustments to Raw files.

Anyone have thoughts on why Bridge, for me, is slow to start regenenerating new thumnails after makng adjustments to files?

My senarios- I open a bunch of raw files (25-100) from Bridge. Opening them with Adobe Raw. I edit/make adjustments to files I've opened, save adjusted files as jpgs to a different hard drive, click "done" in Adobe Raw, go back to Bridge and wait for the thumbnails of the files I just worked on to regenerate new thumbnails that reflect the adjustment I just made. I sometimes have to close/open Bridge to get the thumbnail generation process to begin. Once the thumnails begin regenerating, the process continues quickly and smoothly.