It seems the authors overlooked the case of genertaing thumbnail view of zip files and some files were password protected.
So, if you switch the view of a folder to thumbnail view and this folder happened to have some password-protected zip files, then dopus is gonna prompt you for password once for each zip file and once for each file inside the zip file.
That is, if you have 5 password-protected files each contains 10 files, then you're gonna be prompted 55 times, oh no and without a "Skip All" option, you're screwed!!!
So, I hope the authors put this case into consideration and don't prompt for password during thumbnail generation or at least put a switch to turn this feature on or off.