I have a really weird problem. Basically just convert a char to nsstring and store them in an nsmutable array.

But the code runs ok on simulator, but crash on device.

Here is the crash code, 

```
char t = 'A' + i;
NSString* alphabetString = [NSString stringWithUTF8String:&t]; //substringToIndex:1];
[tempArray addObject:alphabetString];

```

Basically the stringWithUTF8String will return NULL on device, but return valid value on simulator.

```
The device is an iPhone 4s. 

I did not see any notification of changes on NSString stringwithutf8string on iOS5 release.

 Thanks.

```