Thanks for responding, Andy.I am using the latest version (2006) of the International Publisher Edition. But the problem is very specific to my computer, not the edition. That is why I am assuming it is a conflict with a previous installation of MathType. I have the demo version of Lectora and the Equation Editor running on a stationary PC, and there I find no problem in reopening the editor. It is only on my laptop which - it appears - have had a previous installation of MathType, which seems to create problems (with editing a saved equation). Perhaps it is one of these problems that cannot be solved in general because it is so specific to the installation history on this laptop. Michael
