Since multiple HD DVRs here and HD receivers simply don't have any significant impact or issues as you described for the end user experience in this household...and only a fraction of time is spent "directing" our HDTVs for scheduling and programming guide use...it's unfortunate your older device seem to have a problem.
That's not the case with HR24's or newer, which you referenced as well. As others have repeatedly point out...running jet fuel in an older car doesn't usually make it run faster. The same holds true for firmware.
Using that logic makes your HR24 start locking up around 10 days after a reboot just like mine does!
You can't have it both ways!