Вам нужно реализовать URL, который должен отличаться от baseurl.
NSString * userAgent = @"Mozilla/5.0 (iPhone; U; CPU like Mac OS X; en) AppleWebKit/420+ (KHTML, like Gecko) Version/3.0 Mobile/1A543a Safari/419.3";
NSString * urlString = @"http://reader.mac.com";
NSURL *URL = [NSURL URLWithString:urlString];
NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:URL];
[req setValue:userAgent forHTTPHeaderField:@"User-Agent"];
NSURLResponse* response = nil;
NSError* error = nil;
NSData* data = [NSURLConnection sendSynchronousRequest:req
returningResponse:&response
error:&error];
[self.article loadData:data MIMEType:@"text/html" textEncodingName:@"utf-8" baseURL:URL];