So, I'm running QW (ezQuake 3.0 latest build) on my laptop with an external CRT monitor---640x480 @ 120hz, 1000hz mouse, stable 462 fps---but I'm still facing SERIOUS screen jerkiness/choppiness when bunnyhopping or flying in the air after a rocketjump (there's no fps drop).

When I watch demos or spectating online games is 100% smooth.

What's the deal? This is really annoying.

System: Windows 7 Ultimate x64, GeForce 740m (I've tried many drivers with same results), 6 GB Ram.
Sys_highpriority seems to make no effect whatever the value.

I have similar feelings (especially about rocket jumping)on my notebook.
But no external CRT in my configuration.

I even forced to use Intel(!) video card for QW to reduce effect.

God, with Intel Graphics I cant get stable 150 fps...

After having my qw run for many hours now, alt-tabbing back into it I got the same effect! Or rather it's jerky all the time when moving around although not if standing still and moving the mouse around.

We're trying to localize the issue but it seems to be a hard one

EDIT: Does this happen all the time for you guys? Can you try an earlier ezQuake nightly and see if it's introduced somewhere?

When I first tried def's CFG it happened to me. I looked at the cfg's diff and I found it, can't remember exactly, but I think it was cl_nolerp.

That one will make a difference, however the problem I stumbled upon today isn't solved with cl_nolerp. Still don't know what's causing it...

After installing povohat's mouse driver I felt the screen less jerky; dunno why.

I've seen this before and not sure what caused it, my build of EZQ3 is a few months old.