I have a number of class 2 cards and cards I assume are class 1 (since they don't seem to have a class number) and they all work fine.. with the exception of the single card I'm having problems with...

The n900 should not be fussy, it should support all standards cards.. not class 4 or above, that would be ridiculous!

formatting using that sdcard.org tool had no effect.. I'm wondering if my card is defective.. though it is irritating that no other device I own seems to complain..

(I'm going to try it in my N810 now)