Mouse cursor is jerky due to parallel driver states confused.
Cause:
After a computer terminates a Direct Cable Connection using a parallel cable, the parallel driver does not always recognize that the connection was terminated. During the first 30 seconds, the computer tries to detect whether the connection is still active and turns off the interrupt that prevents other hardware interrupts from being used.
Solution:
Wait 30 seconds. The parallel driver will recognize that the connection has been terminated.
