I would recommend you run a heavier ground wire from the HID ballasts to a good grounding point, preferably the battery itself. The stock common ground wire is wimpy as best.
Remove & reinsert the parking light socket while the headlight is out, spray some silicone on it before you put it back in. Mine was near impossible to pull out the first time & I thought the wimpy wires were gonna break. Much easier when it's off the bike than reaching up underneath. after it's been out it goes easier next time.
Oh, and replace the incandescent parking lamp with a white LED, if you don't it looks yellow compared to the HID.