Hello - kind of a weird problem:

When replying to an email, the SIZE box appears under Plain Text. (Using Firefox 3.5.3)
Can not click anything in SIZE box - it will not go away.
Can type the reply, it just does not show until the reply get past the SIZE box.
Does not happen on all emails.
Does not happen when using IE 7.
Tried IE 8 - errors on display inbox - can not get to poing of replying to a message.
In Firefox tried changing fonts, popup's,

System is OES10, GroupWise 8 with hot patch 2. (will be applying SP1 soon).
Any help would be appreciated.