I saw a post yesterday about it, and someone said it was a known issue.
I'm more concerned about how the votes on this post are bouncing up and down between 4 and 818 as I'm typing this reply. Seems like there are some problems here...
EDIT: WOAH this ended up under totally the wrong post. Odd bug...
I think I know what thread you were trying to reply to, and I'm pretty sure the reason your comment appeared on a different post is caused by the same root cause fyi.
Uh... yeah, I had this tab open on an completely different post yesterday and then this morning I tabbed over to it and it switched to this post as soon as I clicked the tab. Very weird stuff going on.