it appears that when i run the tour on my ipad, theres a blank div overlaying 1/3 of the screen on the left, and the combobox is under that's why it's not opening.
this is not happenning while testing with krpano ipad emulator.
there is no 'default' div that would overlap 1/3 of the screen
have you check your html or xml files or elements that could overlap the combobox? e.g. textfields with disabled background are often are problem - their default size is 400x300 and they can overlap other elements of course (even when the textfield background is not visible), an other often problem are elements with alpha=0 - they are invisible but still there for clicking,