Hello there Annie
Well it sounds like you are unfamiliar with yahoo groups that´s all I can say. It certainly IS laid out differently to RISI, but the principles are exactly the same. You will just have to try again!
Perhaps you could find someone to help you who is familiar with yahoo groups and can guide you through it whilst peering over your shoulder.
Although having said that, it IS very VERY easy to join, nobody else is having problems. Just do it slowly and don´t let your internet connection cut you off half way through!
There is no record of your trying to join - no new members have come up for my approval called Annie recently, and there have been plenty of new members who have joined with no difficulty.
You´re not a spy working for the opposition are you? 
But there ISN´T any opposition - everyone LOVES it.. so no, you can´t be.. 
I look forward to seeing you as part of the group.. Where are you based out of interest, if bookswapping out of UK is of interest to you?
Louisa