I haven't had any problems 360 has with bringing up saved files. One thing you can try when you bring up a saved file, go to the graph, and in the lower left corner there is a button that resets the graph to the default settings. While I go through graphs zooming and panning I get lost as to where I am and sometimes I zoom too much and nothing shows up. Try hitting that reset button to see if anything shows up. I always export the jpg and I havent had any problems. How are you exporting jpgs?
Here are some pics of data that I have from doing speed runs. I am using a V3 with a brushless sensor and a 5hz GPS to record speed.