If it's only when you turn the bars and only the high beam, my best guess would be to check:
A) the connection into the back of the high beam. There is a wiring diagram in the Faq somewhere that shows you which wire it is. It's either yellow or white, IIRC. It could be that when the bars are at full lock the wire doesn't have enough slack and is pulled so tight that the connection with the bulb inside the plug is pulled away.
B) the wire going to the high beam has an internal short that is aggitated by the bars at lock and is disconnecting momentarily, disabling the high beam.
I would start by jiggling the connection going into the back of the bulb. I have an S and it is easily accessible but with a naked I guess it would be in the back of the headlight conicle and you may need to disassemble it to access the connection. Also, make sure that the wire isn't getting pulled to tight by visually inspecting the connections at full lock. If your connections are tight and there is slack in the wire, try jumping the wire by connecting a piece directly from the battery. Be careful...you might want to use a leed with an inline fuse. (I would just jump it myself, but don't want you to try it and fry a circuit and hate me
)
This all made more sense before I got half way through the paragraph and remebered you had a naked, but it still may apply.
Good luck!