If crate new VC and init , and release , so it's crash. Please check out.

[RbBtSn0w]

//the view controller you want to present as popover
YourViewController *controller = [[YourViewController alloc] initWithNibName:@"YourViewController" bundle:nil]; 

//our popover
FPPopoverController *popover = [[FPPopoverController alloc] initWithViewController:controller]; 

//the popover will be presented from the okButton view 
[popover presentPopoverFromView:okButton]; 


[controller release];//RELEASE

/** I haven't use ARC , so RELEASE is crash .

*/

//Terminer error message An instance 0x6840420 of class YourViewController was deallocated while key value observers were still registered with it. Observation info was leaked, and may even become mistakenly attached to some other object. Set a breakpoint on NSKVODeallocateBreak to stop here in the debugger. Here's the current observation info: <NSKeyValueObservationInfo 0x684ac80> ( <NSKeyValueObservance 0x684aac0: Observer: 0x683a820, Key path: title, Options: <New: YES, Old: NO, Prior: NO> Context: 0x0, Property: 0x684a0c0> )

[alvises]

Can you check please if ARC is OFF in the settings of the library ? Or are you integrating directly the sources ?