Problems with standard formatting in equations

[Birkebusk94]

Hi
I have a problem with WordMat, everytime I try inserting formatting (eg. A bracket) it crashes my word. So I can't add formatting to my equations.
In terms of bracket i can work around the issue with a / but that is not the case for every function that can be added in a equation. I have reinstalled Word, WordMat, and tried a older version of WordMat - do anyone else have a similar problem and maybe a solution?