I noticed some issues concerning the graphics after I upgraded from Ubuntu 13.04 to 13.10. More specifically:

• Dash tends to be more "laggy" than it used to be.
• When I switch desktops you can clearly see the screen going frame by frame.
• Menu bar is also "laggy". When I open GIMP, the menu bar is useless after a while - it takes seconds to refresh.

The problems seem to appear after some seconds of use. When I boot the system everything works fine, until some more graphics-intensive program starts (Firefox, GIMP, etc).

/usr/lib/nux/unity_support_test -p reports:

OpenGL vendor string:   Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Ivybridge Mobile 
OpenGL version string:  3.0 Mesa 9.2.1

Not software rendered:    yes
Not blacklisted:          yes
GLX fbconfig:             yes
GLX texture from pixmap:  yes
GL npot or rect textures: yes
GL vertex program:        yes
GL fragment program:      yes
GL vertex buffer object:  yes
GL framebuffer object:    yes
GL version is 1.4+:       yes

Unity 3D supported:       yes

I use an Asus Zenbook UX31A with:

• Intel® Core i5 Ivy Bridge
• Integrated Intel® HD Graphics 4000
• Intel® HM76 Express Chipset

Thank you in advance for any answer!