Casio CZ/ VZ/ FZ - Pro Series

hi i've had a casio fz10m for a half a year now
its disk drive was not as responsive as other drives .
i took the drive out of the machine for close inspection 
but when i reinstalled the drive , it failed to read any of the original disks  i had for it .

now don't get me wrong , i had this thing apart a few times and this never hapened  , i clean and maintanence all my equipment, 
so its not a plunder or defective due to my carelessness.

what do we think is wrong ???

anybody had this happen to them ?

anybody know about ther disk drives in the casio fz10m

because now , 

the disk drive acts normal ,
 reads any disk made in itself ,
 just won't read other disks prior to the cleaning

what did i do?
, misallign the heads ,
,unbalenece write stepping?

charles