I'm not sure if the mounting hardware for the '02 is anything like the '06, but I know the '06 definitely does not
use the stock steering stem nut.
The mounting hardware with the Ohlins kit (for the '06), has it's own steering stem nut built into the piece that connects to the front tank bolt to hold the bracket for the damper itself.
Again, the '02 mounting hardware could be completely different, so this may not be very useful, but here's a pic in case it helps at all:
Do you have an actual Ohlins kit (includes the Ohlins mounting hardware), or an Ohlins damper with aftermarket mounting hardware? The Ohlins kit should have very clear instructions on which stock hardware to keep and where to use the Ohlins components.