OCMock argument matching compares classes incorrectly

gistfile1.m

#import "SpecHelper.h"
#import "OCMock.h"

#define EXP_SHORTHAND
#import "Expecta.h"

@interface AFakeObject : NSObject
- (void)callMe:(NSString *)name;
@end

@implementation AFakeObject
- (void)callMe:(NSString *)name {
}
@end

SPEC_BEGIN(StringSpecSpec)

describe(@"StringSpec", ^{
    __block NSString *constantString;
    __block NSString *nsString;
    
    beforeEach(^{
        constantString = @"Joe"; //on iOS 4.3 this is an instance of NSString, on iOS 5.0 it is an instance of __NSCFConstantString
        nsString = [NSString stringWithFormat:@"%@", @"Joe"];
    });
    
    it(@"should pass on 5.0 and 4.3", ^{
        AFakeObject *fake = [[[AFakeObject alloc] init] autorelease];
        id mock = [OCMockObject partialMockForObject:fake];
        
        [[mock expect] callMe:nsString];
        [fake callMe:nsString];
        [mock verify];
    });
    
    it(@"should fail on 5.0 but pass on 4.3", ^{
        AFakeObject *fake = [[[AFakeObject alloc] init] autorelease];
        id mock = [OCMockObject partialMockForObject:fake];
        
        [[mock expect] callMe:constantString]; //on 5.0 OCMock will compare nsString and constantString using nsString.class == constantString.class and fail
        [fake callMe:nsString];
        [mock verify];        
    });
});

SPEC_END