I let the external Sitecom Wi-Fi antenna to works, since the Ubuntu setup. So the connection has worked properly for many days... until it began to fails, despite all Wi-Fi networks are recognized.
As I had to force some update with Synaptic (mainly regarding kernel, updated to 3.13.0-45), I tried to switch to the previous one (3.13.0-31), but the issue wasn't solved.
I'm not sure if it's a consequence of a bad update, but I did this test.
Please help me, my mother needs a stable and "online" PC as it was in the first days, I won't to do newly an OS reinstallation. Thank you