ios - Search Bar not showing on iPhone 4S -

i'm pulling hair out one. i've created view in storyboard:

when i'm running on iphone 5s it's working fine, search bar displayed should. when i'm running on iphone 4s search bar isn't displayed can see in image below:

running on emulator shows search bar correctly in either sizes. in viewdidload have following code:

- (void)viewdidload {     [super viewdidload];      [self.processtableview setdelegate:self];     [self.processtableview setdatasource:self];      self.searchcontroller = [[uisearchcontroller alloc] initwithsearchresultscontroller:nil];     self.searchcontroller.searchresultsupdater = self;     self.processtableview.tableheaderview = self.searchcontroller.searchbar;      self.definespresentationcontext = yes; } 

i found out issue related line self.processtableview.tableheaderview = self.searchcontroller.searchbar; don't understand why. have idea of what's going on here?

have tried
self.definespresentationcontext = yes;

this how implement it:

  self.searchcontroller =       [[uisearchcontroller alloc] initwithsearchresultscontroller:nil];   self.searchcontroller.searchresultsupdater = self;   self.searchcontroller.dimsbackgroundduringpresentation = no;    self.searchcontroller.searchbar.delegate = self;   self.tableview.tableheaderview = self.searchcontroller.searchbar;   self.definespresentationcontext = yes;   [self.searchcontroller.searchbar sizetofit];   self.searchcontroller.hidesnavigationbarduringpresentation = no;