Synaptics makes great touch technology. Their performance and drivers have always been, in my experience, much better than their Alps counterparts.

Except in one specific situation: using the trackpad’s edge scrolling feature in Pidgin.

Turns out the problem is because the Synaptics touchpad enhancer app displays a custom cursor while scrolling in such a way that prevents GTK apps from reading the scrolling action. Not sure on what end the bug is, but the good news is there’s a simple registry fix:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Synaptics\SynTPEnh]
"UseScrollCursor"=dword:00000000

Either copy-paste the above into Notepad and save as “DisableSynTPCursor-FixScrollPidgin.reg” or something less complex, and import it into the registry. Or make the change manually.

Fix thanks to mindelirium88. http://developer.pidgin.im/ticket/10768