Line on display

Hello

I am using the SDT018TFT using the Displaytech supplied register settings.  The only register I have changed is 0xC to 0x0112 to allow me to use the 18 bit RGB interface to display my image.  The clock is 6.75MHz.  The supply voltage is 2.75V.  I have set all the data lines to 0 to display a black screen.

The black display has lines running from the top of the display to the bottom.  These lines are fixed in location, width and intensity.  They are rather subtle, but I would like to eliminate them if I can.  They do not show up very well in a photo.

I tried more filtering on my 2.75V supply, but this didn't seem to make any difference.  Are there any registers I should look at changing or anything else I could do to address this?

Thanks