In order to support Pocket Frogs in the latest version of iOS we can only support devices running iOS 4.3 and newer. This is based on Apple's choice to drop support for these older devices within the latest version of their developer tools. You will probably run into this issue with other apps unfortunately.
You can still continue to run Pocket Frogs version 1.2.2 or older on your device.
Any sets containing new frogs breeds from version 2.0+ will not be completable on 1.2.2 or older versions. When a new set is released, using the "Get New Set" button will skip the uncompleted set.
If you want to transfer your game from a Pre-iOS 4.3 device to a device running iOS 4.3+, please see the following article: http://j.mp/YPicYQ