I know this is an old thread.. but Maybe try setting INTELLIGENTUPDATE system variable to 0?
Controls the graphics refresh rate.
The default value is 20 frames per second. If you encounter problems related to graphics generation or timing, turn off the variable by setting it to 0. INTELLIGENTUPDATE works by suppressing the graphics update until the timer expires. Subsequent updates reset the timer.
The performance improvement significantly affects updates for scripts and AutoLISP graphics. Those using regular AutoCAD commands will not see a noticeable difference in performance.
When I put INTELLIGENTUPDATE on 0 and I run the programs HofYoke.vlx and HofReci.vlx
If INTELLIGENTUPDATE is on 20 then I the animation is more smooth.