SD card reader problems in W7

Dear all.

I have an studio 1555 laptop. I have recently installed W7 x64 but I think my problem is not due to this because I was sufering the same issue using original Vista x64.

The card reader is working only the first time I use it, then, it is necessary to restart the laptop due to this message (excuse me, I am spanish user):

Windows no puede cargar el controlador de dispositivo para este hardware porque instancia anterior del controlador de dispositivo está aún en memoria. (Código 38).

SD host controler version: 6.1.7601.21824, file sdbus.sys

Regarding the SD memory card, controler version is showing the same but, in the details tab, it is showing: 6.1.7600.16385(win7_rtm.090713-1255)

I tried to install the new controler drivers from the file R227769 but it looks it is not working.

Could you please help me?

Thanks a lot.