I have a Mitsumi 4804TE also, copies everything prefect
Read the cd in your Mitsumi to your HD at 4x for copy protected cds, although I have heard that 16x speed read will work also, but haven't tried it myself.
And then burn at 4x and you have a prefect backup.
And get Clony for the correct settings for CloneCD.
I use memorex CDRs 80 mins 16x