This has happened around three or four times within the last two days: the ping counter near on the events tab will read 90293 pings, except when I switch to that tab I'll find I only have less than ten. When I switch pages or refresh the page the right number appears. I haven't seen any posts about it on the first two pages so maybe it's just me?
It happened a few minutes ago so I took a screenshot:

I'm using Chrome on Windows 7, but I have a sneaking suspicion that it happened when I was using a university computer which uses IE (not sure which version of IE and Windows that uses, sorry).
EDIT: Unrelated, but for sometime now whenever I hit the 'Preview Post' button nothing happens...