iphoto calendar

i have an 8 year old desktop. I still run iphoto but recently created a calendar but now I can't buy it. Everytime i try it says account info has changed please approve changes..... which I've done a bajillion times!!! called tech support they sent me an upgrade to operating system 0S X 10.6.3 (snow leopard) and said that should solve the problem.. well surprise surprise, it doesn't. so apparently i've bought that upgrade for no real reason. after march 31 i will not be able to use iphoto at all due to new software they're using now. any idea's on how I can order the calendar?? I tried looking for an iphoto upgrade that is supposedly ilife11 but is that compatible with my older model desktop? any help is greatly appreciated.