When I went to the review overview on Meta on 08.01.2015, 19:16, it listed two open items in the suggested-edits queue, however when I clicked on the queue, I was told that the queue had been cleared. When I went back to the review overview, however, the edits were there again.
Since the icons for recent reviews had not moved, I suppose that these were still the same two items waiting for review, and since phenomenon lasted for half an hour now, I would rule out caching or locked edits to be the reason for this.
After a while, the phenomenon ceased, with one new reviewer popping up in the icon list of recent reviewers.
I had not performed or skipped any suggested-edit review from the queue at that point.
A similar phenomenon occurred for several hours up to 11.04.2015, 11:05: The review overview showed two suggested edits and when I went to the suggested-edits queue, it was cleared. Sometimes, edits that I could review appeared, but two phantom edits remained.