Screen tear and dual monitor problems

[locodog]

I have Linux Mint Mate 17 with 2 monitors, one above another, not side by side.
Problem 1: Screen tear
Graphic card is Radeon HD 4670, witch I know is legacy and no new drivers are available for it. So how do I fix screen tear?

Problem 2: Witch monitor is primary?
After adding second monitor on top of default one, upper monitor became "primary". Main toolbar was on top monitor, all apps are opening in top monitor etc...
So, after doing little research, I found out that there is file
~/locodog/.config/monitors.xml
And there are settings for both monitors with line
<primary>yes (or no)</primary>.
And using that i made my bottom monitor primary and top is secondary. Main toolbar dropped to bottom monitor, and it kinda becamed primary.
There is no rule on witch monitor application will open, at least I didn't found any consistency, sometimes it's top, other times it's bottom monitor. It's not that big deal, I can always move window to monitor I want. Problem are videos, flash videos, youtube and any other websites.
When I open browser, I put it on bottom monitor, but as soon as I hit fullscreen it goes to top monitor and there is no way to make it appear in fullscreen on bottom monitor.
I did found workaround, at least for youtube, I activated html5 and now youtube goes to fullscreen wherever browser window is. But how to make other flash videos go to fullscreen in bottom monitor?

[ibbill]

locodog I would suggest you check this site out. I have Nvdia card so not sure how your radon card works

https://help.ubuntu.com/community/RadeonDriver

Hope this helps