TiVo Transfer (mac) sees TiVoHD but won't show what's on it.

I've been using TiVo Transfer (Part of Toast) and I have version 2.0. Just recently, it has started to "lose" the content of my TiVo HD. Sometimes, after several re-launches, I can have it show me what's on the TiVo and start transfers from it, but after a while, the screen that shows what's on my TiVo is just blank- sometimes while the transfers are still happening.

Most of the time, that window is blank now and it's a real PITA to have to jump through hoops until I _might_ get it to work right again. It sees my TiVo fine, so it's not a media access key issue, but the content on the TiVo is usually not visible. Is this a preference problem? Something else?