Cory Dotorow has really put it best:
TiVo won't save certain shows or allow moving them:
It used to be that it was hard to explain the TiVo. I'd tell people, "It's like a VCR, but it's smart enough to program itself."
Now I've got a new description: "It's like a VCR, but it it's evil enough to screw you over if some rightsholder demands it."
Hey, TiVo: since 1984's Betamax decision, Americans have had the right to record TV shows even if the rightsholder doesn't like the idea. That's straight from the Supreme Court's mouth. I don't know what kind of special privilege the enteraintment industry has offered you in exchange for this spectacular display of wanton shark-jumping, but it wasn't enough. I sold my TiVo when I left California. You can be goddamned sure I won't be buying another one. Ever.
Here's a list of TiVo alternatives.