Black flashing triangles!

Sometimes i get solid black triangles and diagonal lines ‘flash’ beside the deck i am playing, but if a reboot the program it goes away. Seems to be only aestetic but a bit annoying as I have to switch to itunes, for the next song then switch back out to remove this flashing effect.
Anyone else find this?
I have had it happen about 3 times in 30 uses.

thanks

Hi Callum,

Which OS X and djay version are you using? Can you perhaps catch this phenomenon on video?