My S2 does this periodically, but if I try later sometimes it then completes the list. I think it will turn out to be a bug in the program, or how the program is interacting or conflicting with something in the computer.
Like maybe conflicting with the antivirus or antispyware.
I think this just started occurring since the 9.1/9.2 updates.
I think saw it mentioned in some other thread but can't find it just yet.
Tivo HD Lifetime 1TB int, 1TB ext
Tivo 540040 400 GB Lifetime
Tivo S2DT 750 GB msd
Toshiba sdh400 r.i.p.