thats really odd.
I have the X52 if you look @ my sig. I did not have any issues with lock on, in fact it already had it mapped when I launched the game.
-Do you have any other USB stuff attached with axis, etc? (lockon auto maps everything you have pluged in, and this can result in conflicts)
can you get it to map by manually going to the options, selecting from dropdown menu, then axis, then click on throttle then change and finally move it up and down and it should map?
lastly, what version of lockon are you using?
good luck, and dont worry, we'll get you up and running :)