Yeah, check tivocommunity.com. A lot of people have had problems with the last few upgrades. I havent gotten into the dtv units yet, my old series 1's are still chugging along on their 3rd disk drives, 2nd case fans and in one case, a new power supply.
One thing about upgrades that can be a random problem: there are two 'system partitions' on the "A" drive of the tivo. When an upgrade is downloaded and applied, it is applied to the partition not currently in use. Then the system switches that to the boot partition and off you go, switching back again the next time you're upgraded.
Sometimes one of the two partitions has some 'problems'. Tivo's apparently have a grave problem in dealing with 'bad spots' on the disk under some circumstances. This leads to the user experiencing a 'weird' tivo on every other update. The big problem is the user will have some trouble, get a 'fix' or 'later revision' and the problem sort of goes away, so the fix or revision is determined to be the fix. Then it comes back again a year later at the next revision.
I had this happen to one of my series 1's about a month out of warranty. Tivo wanted me to return it and pay for a new disk drive. I used some of the then fledgling tivo disk tools to copy everything to a new larger faster quieter disk and that solved the problem.
Perhaps using mfstool to copy the disk along with its contents and recordings to a new drive will help. If you cant find anyone with a similar problem on tivocommunity and need a good cheap repair job done, check with http://www.weaknees.com
. They fix and upgrade tivos at a reasonable price and are good people to deal with. Plus they're tivo and directv authorized where applicable.