Thank you for your quick response. However, the issue is still present even when using the new version of VectorField3D. The only change I made to the file you uploaded was to remove the old vector field from the view panel. Running the simulation shows random outbursts of vectors (of much greater length than anything I instantiate in code). I haven't seen anything else about this problem - could it be something about the system external to the code that is causing the issue?
PS: I just tried it on another computer and the issue did not show up... I just tried it on a Windows XP tablet edition hp tablet. The issue has been arising on a Mac Pro Quad-Core Xeon running OSX 10.5.6