Using synclient -m, I see that my touchpad returns values for x and y of 1 and 5855 respectively when two-finger scroll has been released. This is considered hard left and down, even though this is "lefter than left" and "downer than down" (LeftEdge and BottomEdge are 1632 and 4281 respectively). This leads to the window scrolling all the way to the bottom left on occasion due to some race somewhere. The driver should disregard these invalid values instead. xorg-x11-drv-synaptics-0.15.201.fc10.x86_64
Sounds a lot like http://lists.freedesktop.org/archives/xorg/2008-November/040592.html Just give me a bit of time to package that up.
Please try the package from http://koji.fedoraproject.org/koji/buildinfo?buildID=73122
Excellent, scrolling is almost rock solid. It feels like the acceleration characteristics have changed, but that might be me.
No, you're right on that. All the accel settings are now autoconfigured based on the device's dimensions so it may be that your settings have changed slightly. We tried to stick as close as possible to the original defaults though to minimise impact.