mount_hfs using all my resources

Hi there,

I'm having some trouble with my time machine HD. It will be backing up and then a window will pop up saying "External Harddrive was not ejected properly...". After this, there will be between 1 and 3 clone drives (I think this is what they're called) mounted in /Volumes. Also, I will get sometimes one, sometimes many, mount_hfs processes running and eating up every last bit of my resources - processor and RAM. I can't force quit anything, it just starts back up, ejecting the drive and getting rid of the clones doesn't do anything. And for the most part my laptop completely freezes up as everything is being dedicated to these mount_hfs processes. This doesn't happen every time but with increasingly regularity.

I have two external drives and it only happens with the on I use for Time Machine. Anyone seen something like this before?

MBP late 2007, 4 GB RAM, 2.4 GHz Intel Core 2 Duo