The B-W relationship when importing an image into Designer has always been backwards (no matter how it was imported). When I started working on CBPE I found out that internally patterns are 0 = transparent, 1 = lowest, 255 = highest. This can cause great confusion if you are trying to make sure certain things are at certain levels.
My best advice is to always make your design take up the full 0-255 range (zero begin the transparent background); with 1 = lowest and 255 = highest. Then when you import into Designer use the 'Invert' tool to 'undo the invert Designer throws in. Then when you use the depth and height in Designer you will always get what you are expecting. Designer expects patterns will take up the entire 0-255 range and if yours doesn't your height or depth setting won't be accurate (as you have a gap on one or both end of your pattern).