Same problem happened to me.

This is related to the hardware. It seems you created an ImageOne array of width*height. Try create an array of width*height*4. Use 4 bytes to describe a pixel, i.e., RGB and alpha. The SLM only uses channel R so GB can be replica of R or anything. Set all alpha to 255. This should work.

Got to blame Meadowlark. Good hardware, shitty interface.

Try Matlab for interface with Meadowlark. Slightly better.