Prints are 1mm short, regardless of how tall the object is.

I've tried searching but I can't seem to find anything specific to my issue.

I'm using Pronterface/Skeinforge 50 on a MendelMax 1.5, RAMPS 1.4, Marlin firmware, Makergear Plastistruder/hotend with 0.5mm nozzle, printing at varied layer heights from 0.2mm to 0.45mm, without fail my parts come out roughly 1mm short. The 20mm calibration block comes out 20 x 20 x 9.18mm. I thought my Z steps per mm was off so I printed a 40mm cube, it came out to 40 x 40 x 39.15mm.

I have turned off the "bottom" section of skeinforge and painstakingly leveled my build platform and set my Z endstop as best I can, and was able to get pretty much one extra layer (not smashing the first layer into the glass anymore), but still off by a lot. On the "Carve" tab I am indexing from layer zero, so I doubt that is the issue.

ever find out why??

Nope.

so is it compressing the whole thing, or only printing the first mm. if its printing just the first mm, you have set the hieght of the machine to only 1mm somewhere on accident. this could be in a few places, in the firmware, in the host software, and in the slicer settings. if its compressed, this may be a slicer issue.

good luck!