My DVR has gotten impossibly slow over the past week or so. It takes forever to bring up "List" and when you select a program it takes forever for the screen to return to normal and the program to be launched. Browsing channels is fine once the channel selection finally comes up. I have restarted the DVR multiple times already. It does seem better right after that, but soon slows to a crawl again. I got this DVR back in 2006 so it isn't exactly new. Any ideas?