I had these symptoms, but I have discovered that this was not an error of Ubuntu at all. My hard disk drive didn't work properly!
When I plugged it in Windows, it didn't show any error message like Linux, just it mounted it without problems, but after trying to copy files it began to show read and write errors. So, as Linux is more thorough than Windows and tries to verify if the device works before mounting it, I thought Linux didn't work properly. -- I can't mount any pendrive/usb-stick or card multireader after upgrade (Breezy to Dapper) https://launchpad.net/bugs/53541 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
