I printed some of the parts and it seems that the fan duct A8 does not fit to A1 properly. In the inventor 1.1 files it looks like the error is 1.5 mm which seems to match what I see in the physical parts.
Thanks for pointing this out. One or two other people mentioned this, I had previously assumed that it was just an issue with some peoples tolerances on the printers they use, but upon further investigation I found that I made some small modifications to the size of the lip at the bottom of part A1 which lengthened the distance from the bottom edge to the fan bracket mounting hole. I have adjusted the part and will be uploading the corrected file shortly to eclips3d.com. Thanks!