I have been running MathType 5.2 and Word (Office 2000) under CX 4.2 and it has worked good. After I updated to CX 5.0 Word freezes at startup. In order to interoperate with Word, MathType installs two files in Words Startup folder "MathPage.wll" and "MathType Commands 5 For Word.dot". When I remove the template file (.dot) from the Startup folder (the path can be found in Words menu: Tools --> Options --> File locations --> Startup) Word starts as normal but without the MathType menu entry and Toolbar. This can be fixed by going to Tools --> "Templates and add-ins" and add the file "MathType Commands 5 For Word.dot" from there.