I was about to raise a comment about exactly this problem, which seems to have been building for the last 6 months. It takes ages to wake up, ages to see my recorded progs (despite me deleting a lot - although I can't find a way to permanently delete the "deleted" progs except to do them one at a time) and ages to access YouTube, etc. Getting frustrating!!
Looks like this is not a unique problem but the last few weeks my box has been very slow to respond when I ask it to do anything - browse my shows, look at channel guide, play recording etc.
Could try and be patient but the delay it's starting to drive me mad.