Try popping out the NAV DVD and see if that helps. Someone mentioned once that the DVD was their source of a slow iDrive boot. If removing the disc makes a difference try a new DVD.
I think the main source of the general overall sluggishness is an underpowered CPU on the CCC versions of iDrive.
Straight lines are for fast cars...turns are for fast drivers
'04 M3 - track
'06 650i Cab - daily driver
'02 Highlander - kid hauler
'01 330Ci - winter beater