Hi There,
I am having the same problem in that Word content pasted in IE works fine, however in FF (3.0.6) I also get the additional meta information.
I tried your example that you linked to and the code pasting in FF worked fine, yet on my own site it does not. Could you maybe suggest a reason why your version works and my version does not?
Unfortunately I am unable to show you the page itself as it is an admin function for a live site, sorry!