For the I/O issue there are a few things you should check/try.
1) When it starts happening reboot go into the BIOS and check your temps. Is your system overheating? (Obviously this means that you know the "normal" temps for your system as well).
2) Try the device on a different USB connection/port.
3) Try a different USB device. (If you don't want to go through the headache of creating another Live USB you can just use dd to duplicate your current one, though it can be slow depending on your system and the devices involved).