CTC Makerbot Replicator 2X ABS issues

Hi,

I'm new to 3D Printing and I'm trying to make something my friend made on SolidWorks.
Here is the problem: It completes the raft, and begins to make the base of the print, and then stops extruding and carries on printing as if it were.

When I take out the filament and put some PLA in there to print something else it works fine so it can't be clogged can it? It looks like it's getting to roughly the same part of the build before it stops. Is it a error in the file or with the printer do you reckon?
It takes around 7 hours to print so I put the extruding speed and travel speed to 90mm/s and 150mm/s respectively. Or roughly that.

Any suggestions would be greatly appreciated :)
Many Thanks.