NSCFString crash app when secondary used

Question

Hello! NSCFString from plist crash my program when i using it in the second time. I have cocos2d project (attach) with one scene and one object. And one .plist file
HelloWorldLayer.h & .m (instantiate from CCLayer)
NodeObject.h & .m (instantiate from CCNode)
Test.plist
In NodeObject i have one local string and two method
@interface NodeObject : CCNode
    NSString *stringForPrint;
-(void)createObjWithString:[NSString *)string;
-(void)printString;
In this both method we print string obtained in parameter string
-(void)createObjWithString:[NSString *)string
    stringForPrint = string;
    NSLog(@"NodeObject.createObjWithString stringForPrint >> %@", stringForPrint);
-(void)printString
    NSLog(@"NodeObject.printString stringForPrint >> %@", stringForPrint);
Plis content is one array with one dictionary whit item type string.
Root
-TestArray <Array>
--item 0 <Dictionary>
---type <String> == "This is string from plist"
For test, into the scene i'm create NodeObject and get dada from plist. And print this string. It's work correctly.
if ([testDictionary objectForKey:@"TestArray"]) {
            for (NSDictionary *tempItemData in [testDictionary objectForKey:@"TestArray"]) {                //It's cool work. True string from plist.
                NSLog(@"type form plist in for loop > %@", [tempItemData objectForKey:@"type"]);            }
I create my NodeObject into the loop. And it's work again.
if ([testDictionary objectForKey:@"TestArray"]) {
            for (NSDictionary *tempItemData in [testDictionary objectForKey:@"TestArray"]) {
                NodeObject *testObj = [NodeObject node];
                //and send it string from plist
                [testObj createObjWithString:[tempItemData objectForKey:@"type"]];
BUT! if i have tried use this string in the printString method form NodeObject, app will crash without log. [testObj printString]; //crash app
I have check object from plist using:
    NSLog(@"Description %@ and class %@",[[tempItemData objectForKey:@"type"]description],    [[tempItemData objectForKey:@"type"]class]);
I repeat. Object creation with manual string work. If using string from plist it's crash. I broke my head. And only in the second method. In the createObjWithStrig it work.
    //Work
    NodeObject *testObj = [NodeObject node];
    [testObj createObjWithString:@"manual string object"];
    [testObj printString]; // Print correct string
    //Crash
    NodeObject *testObj = [NodeObject node];
    [testObj createObjWithString:[tempItemData objectForKey:@"type"]];
    [testObj printString]; //Crash here
I'm attach project file. Can test this

Answer 1

Thank you wery match!
Only this forum help me. Stackowerflow not halped, cocos2d-iphone not helped. Thaks @etresoft
stringForPrint = [string retain];
solved problem.