I ordered two 9 speed road cassettes from nashbar. they are 12-23. Upon
close inspection, I noticed that the spacing between the 12 and the 13
toothed sprockets is slighlty wider that then spacing between all the
other sprockets. Both cassettes came in properly sealed wrappings in
sealed boxes.

Is this normal? I doubt it since all my other cassettes seem to have
equal spacing. Anybody had a similar experience?

Thx,

Andres