I just found this out figured it might help someone else... http://superuser.com/questions/161627/how-do-i-change-the-resolution-of-circles-in-sketchup
Hi In my version of SketchUp 8 the default segments are set to 24. In the answer within the above link I type in 96s which is 4 x 24 = 96 sides this makes for a really smooth circle. Regards El Tel
Kinda feels like autocad, with its resolution settings. For the autocad users not happy with their resolution display, the system variable viewres settles that. Just crank it up to 20000 (maximum value) and you're set.