My Mac App Store account page does not show any options for unhiding purchases.
I purchased Mountain Lion and want to re-download it to make a flash drive, but it does not appear in my purchase history. Clicking Option-Purchases doesn't change anything, and my Mac App Store account info page does not have anything regarding hidden purchases, although my iTunes account info page does. They are using the same Apple ID.
iMac, Mac OS X (10.6.1)