Pattern depth problem

[jerrbitt]

As you can see by the attachment, I cut this pattern and it appeared to cut accuratley. However, as the cut prgressed, the CW started to progressively lower the cut depth. You can see the depth of the edge cut on th rectangle that from a depth of 1/4 inch, by the time it got t the end of the pattern ( aBOUT 10") the depth is negligible.

So what happend?

I'll probably try uploading the pattern again and trying to cut i and hope I don't wast anothr 1 hr and 45 minutes of cutting time plus the board.