[Virtual1ty]

I'd advise you against using that include since it is outdated to use it now, as it was outdated when SA-MP 0.3d was released.
Have a look at this thread here to see what's the "trick" to achieve smooth rotation and maybe even look in the included filterscript "ferriswheel.pwn" too see how it's done.
Then you can re-script your include to use the newest methods available.