GPS Logs Inaccurate
 

I have a 8530 Curve and I installed a 3rd party app that uploads the GPS logs to a web page. The logs were dead on for the first 2 months then they became inaccurate. Usually about a 1/2 mile to a mile off but sometimes as much as 30 miles off of actual location. The app gets the logs directly from the GPS. Any suggestions?