First I apologize for the poor quality of the pic but I lost my digital camera and have to resort to my camera phone. Anyway, I dont have any real concerns because Nikos shell is hard and smells good (other than smelling like an aquarium heh) so I believe it is safe to assume that these are old old baby scutes or whatever that are getting ready to come off.
I doubt there's a difinitive answer for this but why do you think some scutes take so long to come off ? I never really paid to much attention to Niko's shedding but this is probably the second time I've ever really seen some scutes like this with bubbles under them on him/her and I just think it's kinda weird.

Pets1 x Male Rio Grande RES named Niko (knee-co) -
Growth Chart - DOB 7/03/2008 (Owned since 9/24/2008)
3 x Cats (Orange Tabi, Black n Gray Tabi & Black Long Hair)
Feeding ListsNiko: →
Feed Me ← (Updated 6/10/11)
Cats: Cat Food ;-p