System Information
Ubuntu 12
Operating system and graphics card
AMD FX4100 16 GB ram HD 1T Graphic card XFX ONE HDMI (Offboard) 2 GB
Blender Version
2.70a f93bc76
Short description of error
I tried to activate the option Region Overlap on the user preferences. Nothing happened, the panels keep the usual behavior.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps