Because you're iPhone is jailbroken, you need to look at a lot more than just Instagram. Chances are there is something else that interfaces with the UI that breaks it. If deleting it and removing all your instagram data from the phone doesn't fix it, then your job got a whole lot harder because unless someone has posted this exact issue on the web with a solution, you'll probably have to go through remove all of your jailbreak add-ons that you installed and try the app out. If it works start re-adding your add-ons until one breaks the app then remove it and go on to the next one. Keep doing this until you're done installing your custom add-ons. Then if you want to help the jailbreak community send a message to each developer of the add-ons that broke instagram and let them know they need to fix it.
