Equation editor styles when multiple documents are open

[David Apsley]

I use the equation editor in Word. Quite often I need to
change the styles of parts of an equation.

If I have only one document open then I can change styles
in the equation editor quite happily.

If, however, I have multiple documents open then
the styles refuse to change. I have to shut all other
documents down before I can change styles within the
equation editor.

This seems to happen with every release of Word and every
version of Windows that I have tried.

Has anyone else noticed this? Anything I can do about it?