i photo error message

i have an imac g5 powerpc. i have used this computer for two years with no issues. today i go to use iphoto and it won't open. it gives me a message of: "the photo library was created with an unreleased version of iphoto. please quit and upgrade this library by opening iti in iphoto 2 or iphoto 4" when i check to see the info on the iphoto it is showing 5.0.4

i'd love any help