I have also a laptop MSI u270 with ubuntu 12.04 i386 and I have exactly the same problem.
It is weird because I have an external HD disc (WD 750gb usb3.0 caviar blue) and no problem with it. However I can not run usb flash memories. Sometimes the led of usb sticks frezzes on, while other times the led doesn't light.
I already had problems before with ubuntu 11.04 to run SD cards. So I don't miss that, however usb sticks are very usefull, almost essential.
I have also a laptop MSI u270 with ubuntu 12.04 i386 and I have exactly the same problem.
It is weird because I have an external HD disc (WD 750gb usb3.0 caviar blue) and no problem with it. However I can not run usb flash memories. Sometimes the led of usb sticks frezzes on, while other times the led doesn't light.
I already had problems before with ubuntu 11.04 to run SD cards. So I don't miss that, however usb sticks are very usefull, almost essential.