Distance/proximity search does not work with odd ending numbered zipcodes when output should be 0.00mi

using an exposed filter with options zipcode/assume default country and have a location field with options use distance /proximity filter. I collect the a zipcode on a custom content node and allow a distance/proximity search to be done. Everything works great except when you search for a zipcode that matches one that has been entered. This should list 0.00mi because the zipcodes are the same. When it is a zipcode ending in an even number it works and list 0.00mi. When it is a odd number such as 7706(9) nothing is listed, the output is blank.