Replying to The dreaded "X" with variable ND?

i recently bought a LCW fader variable ND ii and took it out to shoot stills. i was shooting late afternoon in arches and had the filter stopped down all the way, 9 stops. even when the sun wasn't in the frame, i got the dark X across the frame. shitty. its not to big a deal with stills cuz i can check them before i shoot them, but im worried about it ruining shots when i shoot video? can anyone chime in? eheath? i think i took his suggestion and bought this specific filter.

i dont really wanna upgrade filters im poor and i know they can get up to like $400. but ill listen to anything...