The problem is with the gfx card settings on different peoples machines.
Personally for those fucking assholes who like to turn off vsync on thier cards, I don't care about them and they can go fuck themselves as they don't deserve to see anything on thier pc.
The real problem is easy to fix.
Some people's cards in 640 X 480 will refresh at 100fps, some at 70fps, some at 50fps etc.
You should NOT delta time the scroll refresh rate as it will always look jerky on things like sine scrolls, but what you could do is compromise.
Get a variable, make it a double and store the timer value in that variable and check at the end of each frame how much time elapsed by saying;
elapsed = timer - oldtime
You will be left with a number that can be divided and used as the addition for your sine wave so at least the wave always moves at roughly the same speed.
IMHO it's wrong to delta time the whole scrolltext unless it's 3D stuff.
