"banditmack" writes:
I have a gsf 600 X, if this helps.
Something is fouled up! Sounds like it's in the paperwork department.
GSF600SX & GSF600X = 1999 model (last year of the first style)
GSF600SY & GSF600Y = 2000 model (first year of second style)
GSF600SK1 & GSF600K1 = 2001 model
GSF600SK2 & GSF600K2 = 2002 model
Perhaps you noticed they were carrying on a pattern, then in 2001 changed to a new pattern since they were close to running out of the earlier one.