If you're using Cairo Dock on Mint 17 & you are witnessing flickering when you hover the mouse over the dock, the fix is simple!
Open the Startup Applications dialog (Main Menu > Preferences > Startup Applications), select the Cairo-Dock entry, & click Edit.
Amend the Command field to read:
This forces Cairo Dock to use the Open Graphics Library at startup and should resolve any flickering problems.
If this doesn't do the trick, try using the Cairo backend:
Sources & References:
- GLX-Dock: Cairo-Dock Man Pages