Why are Keychain services returning incorrect content for keys?

I am trying to use permalink chain links in an iPhone application. I found that if I created two different keychain items, I would get a different permalink each time (they look like "genp ....... 1", "genp ....... 2", .. .), However, attempts to find items using a permalink always returned the contents of the first item. Why should it be? I have confirmed that my keychain-preserving code is definitely creating new items in each case (rather than updating existing items) and is not getting any errors. And as I said, Keychain Services provides different permalinks for each item.

I was able to solve my immediate problem by looking for key binding elements by attribute rather than permalinks, but it would be easier to use permalinks, so I would appreciate a solution to that problem.

Here's my code:

- (NSString *)keychainItemWithName: (NSString *)name {
    NSString *path = [GLApplicationSupportFolder()
                      stringByAppendingPathComponent: name];
    NSData *persistentRef = [NSData dataWithContentsOfFile: path];
    if (!persistentRef) {
        NSLog(@"no persistent reference for name: %@", name);
        return nil;
    }
    NSArray *refs = [NSArray arrayWithObject: persistentRef];
    //get the data
    CFMutableDictionaryRef params = CFDictionaryCreateMutable(NULL,
                                                              0,
                                                              &kCFTypeDictionaryKeyCallBacks,
                                                              &kCFTypeDictionaryValueCallBacks);
    CFDictionaryAddValue(params, kSecMatchItemList, refs);
    CFDictionaryAddValue(params, kSecClass, kSecClassGenericPassword);
    CFDictionaryAddValue(params, kSecReturnData, kCFBooleanTrue);
    CFDataRef item = NULL;
    OSStatus result = SecItemCopyMatching(params, (CFTypeRef *)&item);
    CFRelease(params);
    if (result != errSecSuccess) {
        NSLog(@"error %d retrieving keychain reference for name: %@", result, name);
        return nil;
    }
    NSString *token = [[NSString alloc] initWithData: (NSData *)item
                                            encoding: NSUTF8StringEncoding];
    CFRelease(item);
    return [token autorelease];
}

- (void)setKeychainItem: (NSString *)newToken forName: (NSString *)name {
    NSData *tokenData = [newToken dataUsingEncoding: NSUTF8StringEncoding];
    //firstly, find out whether the item already exists
    NSDictionary *searchAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                      name, kSecAttrAccount,
                                      kCFBooleanTrue, kSecReturnAttributes,
                                      nil];
    NSDictionary *foundAttrs = nil;
    OSStatus searchResult = SecItemCopyMatching((CFDictionaryRef)searchAttributes,
                                                (CFTypeRef *)&foundAttrs);
    if (noErr == searchResult) {
        NSMutableDictionary *toStore = [foundAttrs mutableCopy];
        [toStore setObject: tokenData forKey: (id)kSecValueData];
        OSStatus result = SecItemUpdate((CFDictionaryRef)foundAttrs,
                                        (CFDictionaryRef)toStore);
        if (result != errSecSuccess) {
            NSLog(@"error %d updating keychain", result);
        }
        [toStore release];
        return;
    }
    //need to create the item.
    CFMutableDictionaryRef params = CFDictionaryCreateMutable(NULL,
                                                              0,
                                                              &kCFTypeDictionaryKeyCallBacks,
                                                              &kCFTypeDictionaryValueCallBacks);
    CFDictionaryAddValue(params, kSecClass, kSecClassGenericPassword);
    CFDictionaryAddValue(params, kSecAttrAccount, name);
    CFDictionaryAddValue(params, kSecReturnPersistentRef, kCFBooleanTrue);
    CFDictionaryAddValue(params, kSecValueData, tokenData);
    NSData *persistentRef = nil;
    OSStatus result = SecItemAdd(params, (CFTypeRef *)&persistentRef);
    CFRelease(params);
    if (result != errSecSuccess) {
        NSLog(@"error %d from keychain services", result);
        return;
    }
    NSString *path = [GLApplicationSupportFolder()
                      stringByAppendingPathComponent: name];
    [persistentRef writeToFile: path atomically: NO];
    [persistentRef release];
}