Overhang Issues

Having trouble with my overhangs... help?

EDIT: I originally posted this to link some pictures in a post to a group, not realizing that people would find it that didn't come from the group lol. So here is the original post so this makes more sense.

I got a Da Vinci 1.0a a few weeks ago and promptly flashed repetier and got some hatchbox abs. Everything has been printing beautifully with the exception of overhangs and I just cannot figure out why! You can see some examples in the pictures above.

At first I thought that I was printing too hot and fast since those shelf support pieces were pretty small, but then the 3 pieces that make up a phone camera stand were all printed simultaneously and you can see that all the layers where the major overhang on the tall piece is seemed to mess up everything else... maybe due to the plastic having too much time to cool and curling? Both of these prints ran while I was away so I didn't get to see what the actual problem was during the print.

Does anyone have any suggestions or tips on how to improve the overhangs?

I do have a cooling fan mounted on the extruder that blows at the print and is controlled with slic3r. If it helps, my main slic3r settings are:
Layer height: 0.2 (or 0.1 for high quality)
Perimeters: 3
Infill: 20-30% depending on print
Perimeter speed: 40
Small Perimeters: 25
External Perimeters: 90%
Supports: No
Rafts: No