Pictures not saved

[ocnamli]

using atrix2 for a month now, and having a problem recently; after taking a picture, i sometimes notice that it hasnt been saved in the gallery.
unmounting the sd card and restarting the phone solves the problem temp, however it starts to do the same thing; not saving the pictures. :-\
i have no idea why this is happening, software? microsd? software? phone it self?
thanks