I'm experiencing strange problem with synaptic touchpad: if I scroll with 2 fingers, say, top-down, motion events are generated as usual. Then if I want to scroll further and place fingers upper on touchpad, that touch is detected as motion event in the opposite direction to the point of touch. So attempt to scroll some page, f.ex., makes page just jumping up and down. That happens accidentally, but device behaves that way for at least each 3rd touch.
I'm not sure, when this started. I don't have any other useful information. Though, I hope to get any hints anyway.
Thanks in advance.
Seems like downgrading to linux-lts solved the issue. I've cleaned up pacman cache recently, so can't check more recent kernels.
Just in case if someone's interested.
Here is a bug report on redhat bugtracker describing the same issue in better English
This is very likely to be a regression in upstream kernel.