I upgraded my Dell Dimension 9200C to 12.04 Precise Pangolin with no issues, I ran it fine for a night but when I went back in a couple days later my Logitech Wireless Keyboard K350 and M510 mouse weren't active when booted. I can boot into an older version from the main the boot screen the mouse and keyboard work, but the network stack is gone. It says the networking manager on this version is not compatible. I'm scratching my head, it isn't the mouse and keyboard, they work fine on my dual boot, and they load fine in Knoppix. They did work fine on 12.04 for 1 night. Open to suggestions before I re-install completely.