Given the comments here and on Kickstarter, I'd say that missing hardware--particularly those longer hex-head screws--are a common problem.
Posts made by fnord
Missing parts from kit
I just finished building my kit and came up short two screws. The two missing screws are the ones used to mount the circuit board to the bottom plate. I'm assuming they're supposed to be the long ones (i.e. the ones used for mounting the lower assembly of the "tubes" to the top of the upper plate) since the short ones don't seem to have enough clearance to hold the nut securely.
How do I go about requesting replacements?