Ridges Along Edges

The following pictures are from the chest and arms of this:

http://www.thingiverse.com/thing:170730

Whenever a vertical edge is printed there is a ridge produced - kind of like the edge sticks out a bit further. Any hints on what Slic3r settings or printer adjustments I should make to fix this?

I have a Prusa Mendel (RRP tricolor), Slic3r 1.0.0RC1, 1.75mm PLA.

Thanks, Andy

lower heat and print speed

Also, make sure there isn't too much filament pushed. Make sure you have calibrated your extruder. Measure your filament, print a thin wall cube and measure the thickness.

You need increase acceleration in firmware.
set it to 1500 for X Y.