Due to a change within iOS5, .GPX files are handelled by the operating system differently. This means that opening .GPX files is slightly more involved.
To use .GPS files on an iOS5 device, please follow the instructions below......
1.) Create the .GPX file as normal using the Memory-Map PC application and save it to a location on your PC
2.) Email the .GPX file to yourself as you normally would
3.) Open the email on your iOS5 device
4.) Press the FILE OPEN button (top right of the email window) and select MEMORY-MAP from the menu offered
5.) Open the Memory-Map app as normal on the iOS device (if it does not open automatically)
6.) Flip the screen using the arrow and press the overlays folder icon
7.) Select the type of overlay object that was transferred as a .GPX file
8.) Select the file and press view