We'll respond shortly.
In Chrome, the #banner child element in #HTMLReporter has a 14px top margin. For some reason this margin overflows the parent and pushes the body element off the top of the window. jQuery offset will tell you that the body is offset by zero, but any child elements of body are pushed down by 14px. Try overflow-hidden to remedy.
Specify your ruby version without the --pre tag.
Some pivots have experience with this working pretty well!
Draper/CI Reporter wasn't our problem. Not entirely sure what was - but signs point to a Spork/ResqueSpec loader order problem on Linux only.