In early versions of Word 2007 MetaTexis used to run slowly. Fortunately, in May 2008 Microsoft finally fixed this issue. You can download the hotfix directly from the MetaTexis site:
Alternatively, you can get the file via the official Internet page:
At the top of this page you will find a link to display the hotfix downloads. When you click this link a new page will be displayed where you can request the hotfix. Follow the instructions, and a few minutes later you will receive an email with a link to the hotfix file. Download this file. When you execute it, you will be asked for the password that was also sent in the email.
To install the hotfix, execute the file "office-kb952701-fullfile-x86-glb.exe".