Hi - I am interested in knowing the answer to this too. We have two seemingly identical machines accessing the same website - one works perfectly, one machine see the 'Attach Button' but the button is dead / disabled. If you click back then return to the page it is magically enabled, you can then pick a file but that causes an error.

We have tested on a number of different computers and only one Vista computer with IE9 is having the issue.

Thanks

James