cholme....,
I guess that makes two of us then. I'm a 35 carpenter and and MCSE and it took me months to get a "GOOD" hold on this gray scale artwork. Not so much for "flat" carvings like this but using gradients to get smooth ups & downs for 3D carvings....LOL...STILL drives me crazy at times.
I use PSP and I'm not familiar with Illustrator but I assume it's just as capable as most other decent graphic apps. By looking at you MPC file, it seems there has to be an "outline" of different shades of gray around your letters & pattern. Make sure the shade of gray you have in the middle of them runs all the way to the edges. Designer can "see" ALL 255 shades so if you have any pixels that vary even ONE shade, the CW will carve them.
I can't really tell by this picture you posted but by looking at the results, that's my guess.
EDIT: Wait a second here...LOL. You have it right!! Man I need to wait until my second cup of coffee before typing things...LOL
All you need to do is "INVERT" the pattern in Designer and you have it. Also, adjust your depth to less after you invert it. I'd say no more than an 1/8" (.125).
The way you have it in the MPC you posted, would be the for putting it in a carved region so the letters and patterns would protrude UP from the wood. Attached is your MPC done both ways. I did nothing to you pattern. You have it right.