everyone you readded in the time the friendslist was off and who didnt accept your request in that time is still in your invitation list. the problem here is that you are on the normal friendslist for that person. that means he/she wont get a request even though it says hes on your invitation list. the best way to get him back is to tell that person somehow (ingame for example) to delete you from his list and you do the same and then add him again.