Diagonal print lines pulling up (no replies)

Hi all....just assembled my Mendel90 and it looks great! I printed off the android just fine, and that as well looks great! But, now on my 3rd print, I am having problems. All of my filament spools are the smaller kind, so I need to print larger brackets to hold them. I downloaded the plans off the web, and started to print them out. When the nozzle makes a hard turn printing the fill, the corner looks as if it pops up a little bit, and then that starts to catch the print head and the print is ruined. It is something about the nozzle making a 180 degree turn that the corner does not lie flat. It is probably a setting somewhere, but I am rather new to this.

Thanks! (see attached pic for an example)

(P.S. - All of the skeinforge settings are right, in terms of being set for the Mendel90....I overwrote the configuration file with the Mendel90 one and was able to print off other things, so the base settings are all right...)