i don't know if its even possible to save the captchas with special characters like "#?$*" according to their answers. i know the answers are cached but this doesn't help always and you need to find the captchas with "_" and rename them all again.
furthermore i like an option to select the letters of a captcha by mask, so its easy to find every captcha with a "_" for example.
another feature i ask for is to show or mark all captchas that are conflicting in "Use Mask" when the error "Same Mask for different Char!" pops up. now it shows only one (the last??) captcha when two captchas sharing the same "mask" for different characters.
furthermore it should calculate everything till the end and sort all conflicts at the end or something like that.