It's a Liteon, anything is possible!!! But, it is unlikely that "continued use" has caused it to improve. Considering the opportunities for dirt/dust and other contaminants to get on the laser lens, etc.... More than likely either you have somewhat adjusted your sensitivity to its oddities or some other variable has changed (i.e., your cable signal has improved, you have made minor revisions to your TV setup, etc, etc, etc....)
On the jerky movement, it is also possible that either your media is more compatible or that your sample size is too small. Meaning hold off your judgement until you have recorded multiple times at 3 Hours and see if it returns.
Then again, maybe it just "burned in".