Would it be a good idea to list the conditions when this duplication occurs?
Maybe report back to THIS thread.
OS
Browser/Version
Can the behaviour be intentionally duplicated?
A brief 2 or 3 clear sentences on how you did it.
I've noticed minor (and reproducible) differences when using my home PC using IE8 and FF on XP and when I'm at work using Windows 7. Nothing major.
If we can feed Rev-Ed with enough info then Detective Inspector Technical may be able to nail it.
PS. Surely if it is something as simple as double-clicking then an extra code line disabling the "Post" button immediately after the first click will cure it. It's worked for me in PC programming, but I realise we may be up against code author pride