Tapku library Coverflow problem?

im using tipku library coverflow where they insert different images through this coding, but my problem is that i cannot go with this static method i need to replace it with dynamic one so can use 225 images in it.

covers = [[NSMutableArray alloc] initWithObjects:[UIImage imageNamed:@"0.png"],[UIImage imageNamed:@"3.png"],nil];

i tried this but still nothing happens:

    covers=[[NSMutableArray alloc]init]; 
for (int i = 0; i< 25; i++) {
    NSString * imagestring =[NSString stringWithFormat:@"%d.png", i]; 
    NSLog(@"%@ ", imagestring);
    [covers addObject : imagestring];
    [imagestring releas开发者_StackOverflow社区e];
}
    [coverflow setNumberOfCovers:25];

after using that im getting this error

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFString size]: unrecognized selector sent to instance 0x577d0f0'

can any one help me so i can implement tapku library in to my coding dynamically. or can correct my code so i can use it. thanks in advance.

Please observe following code...

for (int i = 0; i< 25; i++) {
            NSString * imagestring =[NSString stringWithFormat:@"%d.png", i]; 
            NSLog(@"%@ ", imagestring);
            [covers addObject : imagestring];
            //[imagestring release];  
    I have commented this line as imageString is already autoreleased,
 you dont own it so please do not relese it.
        }

What @Toro says is right.

Please use debugger to track where the crash occured. But do make the above change.

Thanks,