I have a 10 iV3. I had a totally different issue and I solved it just last night, maybe you should try it? I found pretty much EVERY critical bolt on my printer had worked lose in the last 18 months or so. Ironically, I also have a find white powder on my gears, but there's no effect on my printing....that I know of. I've yet to print after I tightened everything up.
Maybe some of the bolts on the extruder carriage are lose (some of mine were) causing the gears to misalign?