Perhaps using scp in verbose mode would more informative. The switch for verbose is '-v' so could you try 'scp -v'? Also is there anything in your kernel log around the time when these errors occur?
-- Large file transfer gives error: Corrupted MAC on input https://launchpad.net/bugs/60764 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs