On my previous machine I never had any problems then when I upgraded my computer and moved to windows 7 I experienced the "Jerky Mouse Syndrome". I tried pretty much every recommendation posted in the community to no avail and even tried an emulator to run a virtual machine. While doing that I had to install the software as the administrator even though I had never set up an administrator account. To shorten this lengthy story; I discovered that Draftsight ran perfectly when I log in as administrator yet the same program accessed from my regular account had the jerky mouse. That is the the solution I suggest users try before any of the other complex fixes people have done: set up an administrator account and run your Draftsight from there and see if it fixes the problem.