Problem on releasing memory of UIImageView

[rj2house]

I try to test the following code in Xcode, with performance tool 'Object Allocations'. I found that the memory is still keep increasing. What's wrong?

while (1) {
UIImageView *a;
a = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 210,20)];
[a release];
}