Time and Frame control

I''m not entirely sure if I understood your problem but I''ll give it a shot:

Your entire game(math) relies on updates being of a fixed length. A fixed integration stepsize. Nothing wrong with the idea, especially since it results in simple and fast math.

My problem is that I don''t get your problem (seems it''s not just my problem with your problem, or others would have answered to this problem already) - ''Nuff problems for now

You don''t draw each frame updated every time, do you? Sometimes there are more updates between frames, sometimes less. And this results in jumpy movement.

How about the following:
Don''t make the number of frame updates flexible. Find an Integer so the refreshrate of the monitor is the multiplication of your sustainable Framerate and that Integer. Your Framerate will probably not be as high as before but the animation will be more constant.

But then you do not have a constant integration stepsize, which seems to be the whole point

I will most likely look very newb-ish after this post

Ok, basically I do something like this while coding it:

At the start, I create a variable that holds the starting time:
int StartTime = (tickcount);

Then each time I update, I do this:
int TimeDur = (tickcount) - StartTime;
int Frames = TimeDur / (1000.0 / maxfps);

StartTime = (tickcount)

I''ve took out the casting (so that variables round off correctly). Rendering is done every frame with vSyncing.

Cheers.