I have only received this message 2 or 3 times over the last couple of months, with no obvious effects from whatever is causing it. Now you ask, it does seem to come after I have been using catch-up, which is not something I do very often. I have tried recreating this by going into catch-up again but the message didn't come back.
Yes I have disconnected the power recently because the tivo locks up verey occasionally and that is the only way to clear it. But I haven't noticed any particular pattern to this. The last time I got the error message (last weekend) was since the reboot, but not at the same time.
The only problem I have noticed with the tivo's performance is that in the past few months it has started to run very slowly. It sits still for longer than it used to in between menus i.e. when selecting Home and then moving to my Favourites channel guide and then setting up a programme to record. I can live with this, but it is annoying sometimes.
My main reason for the query was to see if the error message means something important is going wrong behind the scenes.