Cannot open edit merge document pop up.

Cannot open edit merge document pop up.

On my colleagues machine you press merge document field, edit document and it opens in a new window. my login is setup exactly the same as his, with the same permissions, etc, but when i press edit merge document , nothing happens, it just sits saying merging template, no pop up window.

I have loged in as him on my machine and it all works fine, it is just relating to my login, not browser settings.

can you help.