Lag after scrolling

I've set a game I'm making to scroll downward but after a while it lags from 60fps to 30fps even if theres nuthing there. Can anyone sujest a cause?

http://nanoware.no-ip.biz/a1.cap

-Please don't steal

hovers around 85fps for me all the time, even to bottom

It maintains a consistent 75 FPS for me.

Hmm... Odd.

if the scrolling is always one-way (in other words, you don't need to scroll back up ever) you could destroy objects that are no longer visisble/needed and free up some resources.

i set it to 1 instead of 0.5 and now no lag.

Wait a minute, I remember this kind of thing happening with someone else not to long ago. I'm pretty sure it has to do with VSYNC, particularly when the framerate drops below the refresh rate of your monitor. The framerate will half itself then.

Here's the topic where Ashley explains it.

The .cap file linked in the post is no longer online.