Help required for grade engrave (greyscaling)

Hi folks,

Im stuck,

Have emailed the supplier of my machine and so forth and am having no luck

I have a simple 40w co2 laser cutter / engraver, have owned it for about 2 years now, I use lasercut 5.0 as supplied with the machine and it seems to work fine for cutting engraving and so on.

I only in the last week tried to grade engrave, that is burn an image of a picture into the wood, the machine keeps rejecting whatever picture I give it, grayscaled, 1bit 8bit etc.

Can anyone give us some advise on what I Might be doing wrong, or can anyone give us a sample picture to try and gradeengrave with to check if its my machine or the software for prepping the job.

PS I use corel draw for outputting the greyscaled image

Thanks

Steve