20mm-box.stl wont print

When I load the 20mm-box.stl file in pronterface.py the gcode file is created, but no item is displayed in the view of the table. Then if I load the gcode file I get an image on my view of the bed, but when I print homing doesnt happen, no extruding happens and the motors vibrate and the printhead is elevated over the bed. I can print other stl's with no problem, even tried deleting the files and downloading new ones to no avail. Can anyone help, I'm trying to calibrate infill, is there another good file to use for infill calibration?
Thanks

What does Slicer do with the file?

Perhaps you need to wait a little longer for calculation time.

my unit waits a while then pops up about a centimeter than waits some more before it starts to print

the print is still awful but at least it does something.

good luck

The print is happening line by line, but nothing is happening. Waiting wont do any good because every thing is being processed, gcode etc.

For all noobs like me I found if I clicked on the bed the model was off the lower left side of the bed. I have found that when the item is placed off the bed you can use plater.py included with Pronterface and drag the model wherever you want it or click center then export it and it will be back on the bed, I was useing skeinforge, but when I tried to print it the printer wouldnt home, no extruder drive and no Z axis movement, but X and Y worked, so I downloaded the new Slic3r and tried using that to generate my gcode and then loading that into pronterface.py and wala it printed!

Weird,

Sounds like you "start G-code" isn't set up perfectly. what have you done with it so far? mine is this .

G92 E0 ; set extruder position to zero
G28 X0 Y0 ; home X and Y axis
G1 X10 Y20 F3000; Make sure we are over the Glass
G1 E-1.5 F2000
G90 ; Use absolute coordinates
G21 ; Use mm
M190 S60 ; set bed temp to 60 and wait
M109 S200 ; Wait for extruder to heat up
G1 X100 Y100 F6000 ; go to centre
G1 E-2 F5000; Retract
G28 Z0 ; home Z axis again
G1 E0.8 F2000; prep Extrude
G92 E0 ; set extruder position to zero