Ubuntu is doing strange things
 

Recently my Ubuntu 11.10 is having random problems after start up. For example, now I don't have sound and it seems that the videos are running speed up. Previously, I had sound, but I was unable to control it via the main sound level, I mean, when I pressed + or - in my laptop or grabbed the pot meter next to the clock it didn't affected the sound level, only the look of the icon. And I also had mouse problems, the driver freezed i guess.

Can someone tell me what can cause such things?

Ever since these problems have started, have you installed any system updates? Something has definitely caused these issues to arise, and the first step is to try to find out what all changes you have made to your system.

I tried to install VirtualBox and I had to insall libxslt, Qt and libcap. However, I coudn't insall VirtualBox, because "kmk all" command didn't work.