Program deleted because space was needed?

My Tivo is near full. (98%) I set it to record a 1-hour HD program. I verified that it did so afterwards. I could see it in the list.

A couple hours later, I go to watch the program, and it's not there. History shows:

"Space Needed

This show was deleted because space was needed to record other shows on 8/25 at 8:37pm"

There's only one problem. I have nothing set to record automatically. No One Passes. No suggestions. Nothing was manually scheduled to record in the future.

And no one in this house tried to record anything else tonight. No one even touched it, apart from changing the channel to watch live TV.

The Tivo doesn't even specify what it claims it needed to record. And I know that if you do schedule something and then cancel it, it still shows up in history.

But there's NOTHING there.

Does Tivo really get this squirrelly when it's near full?

Or does this mean my hard drive is on its way out?

Frustrating...