I have no idea why this happened, but it looks like my Series2 with a lifetime subscription converted itself to a TiVo Basic unit last night (around midnight).
This morning, I turned on the TiVo and tried going to Find Programs. It was blank (it went to the sub-page, but the only thing on it was the title). I rebooted the machine and it was still blank. I then checked my To Do list. Except for three ARWLs, it was empty. All the SPs were listed as "None scheduled." All my manually scheduled individual programs (like movies) were gone. Also, my Suggestions page was empty.
I forced a connection and watched it successfully complete. Nothing changed (though it could be because I didn't wait for indexing to complete). I looked in Recording History in the To Do list and noted that some items (my manually selected individual recordings) didn't record with the following reason:
"This program was not recorded because it was scheduled with a TiVo Plus service feature. To upgrade to TiVo Plus service go to TiVo Central and choose "How to upgrade to TiVo Plus service.""
There was no such menu item (thankfully). I checked System Information and everything looked OK. My TiVo Account Status said "5: Product Lifetime Service" and my TiVo Service Level said "C: 072307" (I have no idea what that means).
I then went to my SP Manager and moved the top SP down one spot (thus forcing the whole To Do list to rebuild). When it finished, the To Do list contained my ARWLs and SPs, but those individually scheduled programs were still missing. I looked through the Recording History again and noted the "TiVo Plus" ones that should have been scheduled soon, went to Find Programs and set them up to record again. No problem (I've still got to find the ones that should have been scheduled farther out).
As of now, it looks like the TiVo is working correctly. My guess is something got messed up during a connection to the TiVo servers last night (around midnight where my first "TiVo Plus" recording showed up in Recording History). I'll guess that my Account Status was wrong. I wish I had checked System Information before forcing the new connection. Anyway, I thought I'd report it here just in case other people have the problem.