When viewing the details of a suggestions, the suggestion's ranking is displayed on the right. The problem is that these rankings currently include completed items. So (for example) while currently the "Allow members only site" suggestion has 19 votes and is 3rd place in "top ideas" viewing details says that it is 4th ranked, because one of the completed items has 21 votes.

Once an item is marked as completed it's ranking should no longer be displayed when viewing details (maybe display "Completed" in that space instead) and the rank of active suggestions should be adjusted appropraitely.