it might be worth trying makerware - just to try and eliminate the slicer as the problem.

Any idea what file format the dreamer takes ?
ie: gcode, x3g or 'other' .

One other thing - when you do the dual colour prints - does it print a wipe wall around the prints ?
If not then the ozzed filament the wall normally gets rid of will collect round the edges of the print.

It's my one issue with simplify3d - no wipe wall (well it has one but doesn't actually work) so lots of excess filament all over the place.