Getting a dialog from a separate process to be on top of everything else is amazingly difficult.
Microsoft seems to have decided that this is not a good thing, and it was made like this about the time that Vista came out.
The dialog icon is in the toolbar and clicking on it in the toolbar should bring it on top.
I've got some code I use now for this which seems to help but even so I don't think it is 100% reliable.
I agree that it's annoying but it isn't broken and so I don't think it justifies a new release of the ASCOM driver.
Chris (who wrote the ASCOM driver)