Single Extruder Print, but both extruders preheat

[samiampersand]

Hi All. I recently got a FlashForge Creator Pro and have, up until now, only been using the right extruder. I have recently begun testing with the left extruder, but when I try and print something with just the left extruder, it heats the right one as well. This is especially a problem because I have ABS in the left and PLA in the right, so either I have random bits of PLA dragging around the plate, or the machine tries to extrude solid PLA before the print starts. I have checked the gcode, and the machine IS getting the command to heat the right extruder as well as the left, but I have nothing set to print with that extruder. I am using MakerWare with no raft or support. Any advice for fixing this? Thanks!

[warkmal]

It's caused by the slicer and your start gcode. What are you using to slice? Also, share a sample gcode file.