Eagle Tree Datalogger on the horizon for me, anything I need to know

I've been fooling with my V3 lately - amazing to see 100amp spikes in a Slash (no, its not stock...), but what's the secret to saving and re-using these files??

Everytime I try and save one, there's nothing in the file when I try to reload. I remember something so time back about .CDR vs .FDR files or something, but I can't find it with a search.