SD35 Recording Question

Hi, all you MIDI types:

I use a Roland SD35 file player and synthesizer to record my sequenced
MIDI files.  But I have always had trouble with this process and wonder
if anyone out there knows  where the trouble may lie.

When I record several sequenced arrangements on the SD35 file player
disk, sometimes (most of the time) there is always a song or two which
do not replay sounding the same way it was recorded.  In other words,
the initial set-up of the "program" (ie tone choices - flute, brass,
strings, etc.) is messed up.  Sometimes I spend a great deal of time
recording 10 - 15 songs on the disk and only later learn that smack in
the middle of the disk is a selection with a horrible sound because the
"program" set-up commands got messed up.  The song sequence is
carefully selected so this mess-up becomes a difficult problem.  I have
to start all over again.

According to Roland's directions, some MIDI information can be lost if
you allow the SD35 to automatically start up on the first signal it
receives.  So I avoid that route and start the recording process and
then go to my computer to start the sequence.  This works well most of
the time.

Now, when I finish the recording I could go back to the SD35 and listen
to the piece.  But this is not a valid test  unless I purposely mess up
the "program" settings by playing the first measure of another piece.
You see, if I do not do that,  then I will never know if the piece lost
its "program" information and if it will sound bad when played after
another piece.

I have also had trouble copying a disk on my Mac  made by the SD35.  I
am suspicious that the SD35 is a "brute force" machine, which formats a
disk and records,  come hell or high water.  In other words, there is
no checking for bad sectors.  So, I reasoned, one must use a perfect
error-free disk.  I've had very bad results using Mac-formatted (for
PC) disks in the SD35. The computer can keep track of bad sectors, but
the SD35 can not.

    Question #1 How can I get error-free MIDI recordings?

    Question #2 Are my assumptions in the last paragraph  true?

    Question #3 Where can one get a perfect error-free disk?

    Question #4 When formatting a disk, how can one "see" if the disk is
                error-free? (By the way, I'm a MacUser. The Mac can
                format PC disks.)

    Question #5 The Mac directory calls the Roland SD35 files "PC Exchange"
files.  Is there a way of making such a file from my
sequenced files on the Mac?

I know the questions are many. Any answers would be appreciated.

Thanks.
Andy LaTorre