Customising error messages

Is it possible to reword the error message displayed when a user has a popup blocker preventing launching new windows for things like preview, content editor, view properties, audit trail, etc, from inside the 6.5.2 Content Explorer. At the moment, it just says…

Unspecified error invoking method or accessing property: showWindow

…which isn’t user-friendly.

Apparently, the behavior of the browser has changed, causing our behavior to change. We used to display a user friendly message if no text was returned from the browser. Now text is returned, and that is what we show. It would require a code change to affect this message.