Many times (not not always??) when I post reply to a post (which is what I do 99% of the time) I get the following message:

Name:  codeguruerror.png
Views: 78
Size:  26.7 KB

After pressing Leave this Page the post gets published.

I should mention I use Chrome and I've seen this, but I only get this problem with Codeguru (and I'm using this Quick Post feature on other sites too).