ubun2^beta

I got sony viao PCG K115z laptop. It has got memory stick pro slot as all the viaos,
After this description, My computer freezes during installation. I tried the live CD it happened again. after many unsuccessful trying i pressed f6 and put the cross sign next to first option (acpı off) it worked. then i did the same thing during installation and the installation was ok too but my problem starts here, my computer again freezes when i try to get on most of the time and it happens always in section of loading UBUNTU. Sometimes i see the logo only (Ubuntu logo) sometimes it passes there and freezes right after login name after password and sometimes freezes in few minutes after i see the desktop and rarely it works without any problem. (maybe one in 10 trying) I dont do anything special when it got on without problem. ı press the button and pray for loading.
I installed the latest (9.10) just few days ago and didnt install any other program yet. So there shouldnt any other program casused this problem.
I guess it casused by my memory stick cos its lights gets on as soon as i choose ubuntu instead of Windows and never gets off. when i use windows, the light gets on and check it and get off again until i use it. If i dont use it never lights up.
I had the same problem for windows sometimes ago and i changed the driver of memory stick than there was no other problem. But on ubunutu i dont see this device or its driver (if there is drivers for devices (sorry so new to Linux))
I tried to disable to this device from setup of my computer but there is no option to enable or disable any device on its setup menu.
Please help me on this issue,
my email address: erdinckargin@hotmail.com