Thanks, unfortunately when trying to track down bugs, I really need a simple script that reproduces the specific issue being reported.
Regarding the custom dialog, I have just noticed that some time ago I added another custom dialog "option" type, in addition to (dbu, pixels, notheme, disable), called "map". This performs the same function as "dbu" but is specific to the dialog being displayed. "dbu" is generic but has to be kept as it is for backwards compatibility.
If you try using "map" as an option type in the dialog definition, does that resolve the issue?