I had an iPad 1 and used an external GPS (Dual XGPS 150) for flying. It worked perfectly.
Just bought iPad4 and it will not pair with this GPS for some reason. It will recognize its existence sometimes and try to pair, but then I get the message, "Pairing unsuccessful. Make sure it's turned on, in range and ready to be paired." It is turned on, freshly charged, and right next to the iPad.
Sometimes the iPad won't even recognize that it's there. It will pair with an Apple keyboard without difficulty. I've reset to the factory settings but it doesn't help. Ideas anyone?