BScan - 9:09 am on Jan 31, 2007 (gmt 0)
I had same experience. Also can tell it's a glitch.
Some of the pages wasn't in index 2-3 weeks, and after that they are back. That problem I saw first time before 2 months.
I can't tell how many pages are affected (because it's a large site), but I know that Google sending traffic again for main pages.
Probably there are some of pages which still have that problem, but they are not so important to track.