objective c - Core Data not returning results on one device, working on all others -

i have devices here, both equipped core data application. problem is, when build device (development build), , sync itunes 3 devices (2 iphones 3gs , ipad), application works correct on 1 iphone , ipad.
on other one, doesn't return records (from prepopulated sqlite database).

the device on not working not set development device, other 2 are, correct profiles installed , application runs except not fetching records.

any ideas because i've never seen before. i've tried restore no success.

solution: not figure out cause was, restore , setup new device solved problem.
fact data in backup lost did not matter since demonstration device , did not contain important data created using it.