DBRpcTask response block not called.

Here is the code.  I tried to make it as minimal as possible but I think the pattern is clear.

- (DocumentMetaData*) createFolder:(DocumentMetaData*)folderInfo {
    NSURL *folderURL = [folderInfo itemURL];
    NSString *folderPath = [[folderURL path] stringByReplacingPercentEscapesUsingEncoding:UTF8Encoding];
    DBUserClient *client = [self getDropboxClient];
 
    [[client.filesRoutes createFolder:folderPath] setResponseBlock:^(DBFILESFolderMetadata *result, DBFILESCreateFolderError *routeError, DBRequestError *networkError) {
         if (result) {
             if ([delegate respondsToSelector:@selector(checkFolderCreated)]) {
                 [delegate checkFolderCreated:YES];
             }
         } else {
             LALog(@"%@\n%@\n", routeError, networkError);
}
}];
 
    //Wait-loop for create folder request with the given timeout
    NSDate* giveUpDate = [NSDate dateWithTimeIntervalSinceNow:TIMEOUT_CREATE_FOLDER_IN_SECS];
    while ( (self.currentRequestStatus == REQ_PROCESSING) &&
           [giveUpDate timeIntervalSinceNow] > 0) {
        //Keep looping.. Run the current run for a millisec for the Network and UI async events to be taken care of
        NSDate *stopDate = [NSDate dateWithTimeIntervalSinceNow:0.001];
        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:stopDate];
    }
 
Delegate Class:
 
- (void) checkFolderCreated:(BOOL)success withInfo:(NSDictionary *)infoPassedIn {
DocumentController *docController = (DocumentController*)[infoPassedIn objectForKey:@"DocumentController"];
     if (docController == nil)
        return;
 
…
 
[docController createFolder:docMetaData];
 
…
 
// some condition to pop out.
}

Here the first call to createFolder successfully has its response block called.  All additional calls execute the createFolder method (the folder is created) but the response block is not called.

The while loop is used to make the call synchronous in this case.  This may be interfering with the response block being called back but not sure.  Any ideas?