I use 12.04 precise long term service release. I bought a USB 3.0 adapter which repleaces the DVD player and comes with two USB 3.0 ports. After, I have upgraded some time ago to linux kernel >3.0.20 the module for USB 3.0 (xhci) disappered from the kernel. I was suprised because I would expect USB 1.0 to disspaear not a newer technology. But I found a way to make it work again.
Thanks to this website I had the idea to upgrade my kernel from Ubuntu Kernel mainline. So, I found a post who did this before and applied it. My USB 3.0 controller works perfect. Here how it goes. Check the mentioned website for 32bit operating systems. Below you can only find 64bit.
$ mkdir v3.10
$ cd v3.10
$ wget -c kernel.ubuntu.com/~kernel-ppa/mainline/v3.10-saucy/linux-headers-3.10.0-031000_3.10.0-031000.201306301935_all.deb
$ wget -c kernel.ubuntu.com/~kernel-ppa/mainline/v3.10-saucy/linux-headers-3.10.0-031000-generic_3.10.0-031000.201306301935_amd64.deb
$ wget -c kernel.ubuntu.com/~kernel-ppa/mainline/v3.10-saucy/linux-image-3.10.0-031000-generic_3.10.0-031000.201306301935_amd64.deb
$ sudo dpkg -i *.deb
If you do not know what is your USB 3.0 controller is you can see in the reply of the command “lshw”.