On both my iPhone and iPad running 5.0.1, I cannot open many PDF attachments. Some work fine, some don't, and they seem to be consistent between both devices. All these attachments work fine on OS X Lion. The attachment will download, and once it is completed, it reverts back to the same download icon and then will not open at all. I have searched online for the past hour and can't seem to find someone with the same problem. I have been removing and adding back my Gmail account to no avail. Anyone can help?