Blender 2.69 on Ubuntu 13.10 not detecting CUDA

I just downloaded the latest stable release 2.69 for GNU/ Linux from the download. To test against the buildbot releases.
The one problem I found is that it does not detect CUDA on my machine that is running Ubuntu 13.10, on AMD FX 4500 4 core with 12 GO ram and an nvidia geforce GT 640 w/2 go ram See snapshot from screen

Also the Ctrl-M does not merge anymore vertices.

The usage of my Wacom tablet gets sudden slow down that last a second of two and then goes back to normal.

The limit selection to visible seems not working, being always in full depth state, it is not possible to select front to camera vertex or edges or face. Get always to the bottom of the object one is working on.

In opposite I work with the buildbot versions and I have none of these issues with them other than the limit selection to visible which creates problems and we should be able to enable or disable it at any level and not like currently having to tab and Z to have access to it.