Lost months with core data

I am storing dates in a core data data file whenever th开发者_Go百科e user uses my app and then displaying them back to the user. For some reason, just every now and again, i get an entry with the the right day and year but the month has dropped back to the fires. Has anyone heard of this happening in the past and know how to fix it? Everything seems unaffected (ie time, days and years) except month. It only ever changes to january (IE it either works right eg 23/5/2011 or it defaults to january eg 23/1/2011) Thanks to anyone who can shed some light on this or can even point me in the right direction as to finding the problem as so far it looks random thanks

Found my issue. It wasn't random, it only happens when I quit the app then go back in. I wasn't handling the date correctly when I feed it back into the app.