David,
As far as autoclean on the L700, we've had it on on both of ours and have
yet to experience problems with it.
 Is this 84 error the only one you've received? Have there been other
read-write-position(84-85-86) errors? I just recently got done fighting a
horrid battle with these errors. Mine turned out to be hardware but the
options for cause were many and widely varied.
 
 Troy Deterding
AeognUSA