'Missing Fonts' Alert Box gone missing

We’ve got an XP/CS3 Web Bundle set up and have a problem with Flash not displaying the ‘Missing Fonts’ Alert Box when we open up a file that required fonts that we haven’t installed.

We still see a

“[FONT=Tahoma][FONT=Verdana]One or more fonts used by this movie are not available.[/FONT][/FONT]
[FONT=Verdana][FONT=Tahoma][FONT=Verdana]Substitute fonts will be used for display and export. They will not be saved to the Adobe Flash authoring document[/FONT].[/FONT]” [/FONT]
[FONT=Verdana][/FONT]
[FONT=Verdana]error message in the Output Window and we can see which fonts are missing in [/FONT]
[FONT=Verdana][/FONT]
[FONT=Verdana]Edit>Font Mapping[/FONT]

[FONT=Verdana]but regardless of file, we don’t get the ‘Missing Font’ Alert PopUP.[/FONT]

Tried setting warning prefs, deleting prefs and even reinstalling Flash but still have the problem

Anyone else experienced this and managed to fix it?