Well Safari has been acting strange here for a while now, crashing daily (on any site) and I still don't know why. I wouldn't be surprised if it is related.
It still exists unfortunately. I reinstalled OS X completely recently (10.6.6), Safari 5.0.3 still shows the bug. I can't imagine I'm the only one experiencing this?
I'm using a Macbook Pro from late 2008 with all software and drivers up-to-date. The graphics card is a NVIDIA GeForce 9600M GT. I have no flickering on any site or any other XF feature, just that likes pop up when scrolling.
PS: the following/followers pop ups in the profiles also do not flicker when scrolling, so it's just the likes pop up.