Out of curiosity is that one page in Google? As I understand, the site has to be indexed. Do not know if you have one page indexed with no page rank what the answer would be. Shannon
If they are indexed with PR3 and everythings working as it should I don't see a reason why your weight would be 0 - it's not going to be good though! Unless that page isn't actually cached by Google!
I have a weight of 2 now. I have no idea how it's figured but if you have PR than you should be above 0.