There is a Macam component patch that will fix the stuttering image problem associated with the Kensington VideoCam 67014, 67015, 67016, etc. and perhaps other brands. If you have the image stutter and jumping, replace the Macam.component that should be in your Library->Quicktime folder with the patched version available here:

http://homepage.mac.com/lonsing/macam/

Note: this patched component is different than the "patched" Panther version of the Macam application & component available here. You use the Macam application from here (or any other app. such as Videoviewer, etc.), but replace only the macam.component with from the address above, which is what actually enables the camera (without stutter).