I can no longer leave an app review in the iTunes store

I can no longer leave an app review in the iTunes store.

After I sign in, and want to leave a review I get the following message: "You must own this item to write a Customer Review. In order to write a Customer Review for this item you must have purchased or downloaded it."

I used to be able to write and edit my reviews which I have done! But now I can't anymore even though I have bought and/or downloaded several apps. iTunes won't let me write a review anyway.

Any help is appreciated.