What is your address and location ? Google does have region-specific instructions. For indians and people from few other asian countries, they have a rule that the domain should be active for atleast 6 months before they approve it. I first applied for adsense for my blog 3 months back. That got rejected with this reason. As I understand, the same rule applies to my hubpages account as well. Irrespective of the traffic or my hub count, google would not approve my account till my profile is 6 months old.
However, if you are based out of US, then it is a simple job. You just need to have 5 or 10 original and quality hubs that follows their policies.
I find the policy quite discriminatory but i don't care much as I write only about things that I love and am not exactly eager to increase my hub count :)
Ads would anyway continue to appear in ur article because hubpages gets its revenue out of that. This is how they are able to give us free space to write !