Lockup and/or video drops in both recorded and live broadcasts

Ever since the software update allowing double play my system is not working properly on most HD channels, but not all.

On ESPN and ESPN2 especially, I get lockups and dropouts almost all the time both in live and recorded broadcasts whenever I try to rewind or FF. I recently dropped HBO but had problems with lockups there as well but nowhere near as bad as the ESPNs. I currently have Showtime and haven't really seen a lot of problems with these channels. Comedy central at times locks up. I never seem to have a problem with my local HD channels, at least not nearly to the extent as on the ESPNs..

Now in addition for the past week or so I'm consistently getting audio drops of a second or so on virtually all HD channels, (again except for the local channels) several times per episode.

Changing channels or scrolling or trying to enter channel numbers through the guides is abysmally slow,at times nonresponsive for up to 10 or 15 seconds..

I also hear something like a slight grinding noise from the receiver a lot, I do not know if it is the hard drive or the fan, again this seemed to happen several months ago after the doubleplay software was uploaded.

My receiver is an HR20/700 and my software version is 0x40c., updated 8/31 8:24AM.

Any ideas?