I noticed this answer (now since deleted, and 10k-only) on SO that had a number of canned comments which indicated to me that it had entered the Low Quality review queue.
Noticing the answer was still around, I went to the Low Quality queue to cast my delete vote to clean it up. However, when I went to the review queue, it showed 0 items to be reviewed. When I clicked on the "Low Quality Posts" link, I got the message:
There are no items for you to review.
However, when I went to the History tab, I saw the answer in the history. I then saw Bohemian's vote for the question, and clicked on the "Delete" link next to it, and I was taken to the review page where I could then cast my vote.
The question: if this was a valid item for review, how come it wasn't showing up in the review queue? I had flagged it as Not An Answer; could that cause it to be excluded from my review queue list?
Update: It happened again with this answer, which I hadn't flagged, so it's reproducable and not related to flagging.
I haven't naturally seen a LQ question in the queue in weeks; I've had to look at the history tab and vote from there.