facebook app does not support ios 4.2.1!
why my ipod touch 8gb ios 4.2.1 cannot be updated to ios 4.3? facebook app does not support ios 4.2.1!
iPod touch, iOS 4.2
You have a 2G iPod. Those can only go as high as iOS 4.2.1
Your only way is if you have the version that was compatible on your computer such as in the recycle bin/trash or in a computer file backup. In that case delete the current version that is in your iTunes App library and replace it with the older version. Then sync.
Otherwise you either have to use the FB website or get a newer model iPod