Gear Cube Slic3r Settings

[videospecialist46]

I've printed many successful prints, but I just can't seem to dial in on the right settings for the gear cube found here: http://www.thingiverse.com/thing:50716. The corner edges of the parts start to curl up on about the 10-15th layer. Any ideas? Here are the settings I'm using in Slic3r:

40mm/sec Perimeter speed
30 mm/sec infill speed
.3 Infill
Infill every 1 layer
Only retract when crossing perimters
Infill before perimeters
.6 Extrusion width for all fields (Advanced setting)
8.4 retraction length
6mm Z lift on retraction
40 mm/sec retraction speed
.25mm extra length on restart
3mm minimum travel after retraction

Attached is a pic of what the curling on the part looks like.

[foshon]

Does the base always curl off the glass like that? If so I would look at solving that first. As that part curls up your layer height/wall position settings become void.