Hi there we've got the same issue here on some users I'm looking for solution too.
Is there a bug posted on this ?
Just to add some information, it could come in use:
The problem is in the users PC thats for sure because the majority here works just fine.
One of the problematic PC's is running win 98, other - XP. Both have IE 6 installed.
On the XP machine all toolbars etc were removed just to make sure its not them causing the problem.
We're running SVN 360, also the js error here is reported on Line 2, Char 36xxx (I don't recall exactly).
There must be some code in the javascript compose uses that's incompatible with older browsers, if IE6 can be called so at all...