I've been running Mint 13 Cinnamon 1.4 for about a week, no problems. I've had the "panel" set to autohide since install.
Today the display started breaking up briefly every time the mouse crossed the boundry between the desktop and the "panel"
The problem disappears if I disable "autohide".
In fact, the break up occurs when the check box in Cinnamon Settings is checked or unchecked.
Only two things changed just before this started.
1. Auto Update installed several updates. I didn't pay any attention to what it was updateing.
2. Using ADDITIONAL DRIVERS I tried to install propriatary drivers for my display card.
ATI/AMD proprietary FGLRX graphics driver (post-re;ease i[dates)
ATI/AMD proprietary FGLRX graphics driver
The install failed. The log was 44KB of stuff I don't understand so I don't know exactly why.
The Additional Drivers app continues to say "This driver is not activated"
I've run Ubuntu 11.04 on this hardware for 8 months with no hardware problems.
AMD Athlon II X2 240 2.8 ghz, 2 mb cache, socket AM3
Chipset = AMD 880G/SB850
OnBoard display = Radeon HD4250 GP, 256MB shared RAM
RAM 4GB DDR3, 1333 dual channel
Monitor Chimei CMV-24EH, 23.6 Wide LCD