Hello guys,
I have a problem with firefox 27.0. When I scroll firefox almost every time draw black lines into webpage. In other webbrowsers it doesn’t appear. I’ve tried to find solution on forums, bud without success. Did somebody have this problem or can somebody help me? I’m including picture of this bug.
I have Lenovo u430p with core i5, full HD display and intel iris 5100 graphic card.
http://s8.postimg.org/irqikybdx/Sn_mek_z_2014_03_07_10_25_10.png
From a terminal, do:
firefox -ProfileManager
Create a new profile, test there. See if the problem is gone.
If not, create a new openSUSE user temporarily, test Firefox there.
Thank you for reply. I’ve tried to create new user in firefox and it didn’t work, so I’ve tried to make new opensuse user and it seems to solve this problem. When I returned to my old account the lines doesn’t appear. 
Have you installed and configure sub pixel fonts and hinting from an outside repo in your normal account?
No I guess I didn’t. I only changed size of system font, because it was too small.
Please try doing a rename of your hidden .mozilla folder
To start a new mozilla folder
Just to be sure
Rename rather than delete means you can go back to your original
Well I did it and it started to do it again, but less then before. It means that I have to scroll chaotic like upside-down and after 15 seconds of this that lines appear. When I scroll normally that lines disappear.
And It’s doing it even in firefox 27.0.1, because I’ve updated my firefox today.
But a new user is fine??
Yes, new user seems to be fine.
It suggests to me that you have made some changes in the normal user profile that is causing this. What exactly…who knows.
The solution is staring you in the face. But it’s long winded whichever way you do it