I should have confirmed that it's the exterior (visible) part of the weights that BiG DoM is referring to as being different lengths. It's nothing to do with poor fitting - the weights are different lengths. I only noticed because I took mine off to fit renthals.
Sounds like a mod that they made on '06 bikes (GS and GS Adv) - maybe those people who have matching weights have pre-'06 (i.e. outdated and inferior

) bikes?
And Wizard, are you looking at an up to date parts listing or one from last year?