I wouldn't put much faith in the accuracy of the Zillow estimates for valuing your home. The algorithms utilized by Zillow are designed to estimate values on a national basis, they are not optimized around Florida, Lee County, Fort Myers or Whiskey Creek.
The truth of the mater is that values in Whiskey Creek have been flat for the last 16 months. Here is a comparison of Whiskey Creek sales in 2010 vs 2009:
2009 sales: 74
avg, selling price: $185,186
2010 sales: 26
avg selling price: $187,013
Whiskey Creek homes continue to be a solid investment choice in the Fort Myers area. With its location parallel to the Caloosahatchee River, the McGregor Boulevard Corridor will hold value long term better than locations further away from the river. Here is a resource to view active Whiskey Creek homes for sale: http://www.greaterftmyers.com/whiskey-creek.php