title: Cannot find peripheral when scanning for specific service CBUUID
body: <p>When I use:</p>
  
  <pre><code>CBUUID * uuid = [CBUUID UUIDWithString:@"1800"]; // GAP
  DEBUG_LOG(@"CBUUID: %@",uuid); // CBUUID: Generic Access Profile
  _centralMan = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
  [_centralMan scanForPeripheralsWithServices:[NSArray arrayWithObject:uuid]
                                      options:nil];
  </code></pre>
  
  <p>I cannot find my peripheral, but when I use:</p>
  
  <pre><code>_centralMan = [[CBCentralManager alloc] initWithDelegate:self queue:nil];
  [_centralMan scanForPeripheralsWithServices:nil
                                      options:nil];
  </code></pre>
  
  <p>…it shows up immediately.</p>
  
  <p>When I connect, I am able to discover/read/write to all the services I am expecting. My understanding is that GAP makes this possible. I have also tried <code>CBUUID</code>'s for other services that I know are running (specifically "1804", TX power service), to no avail; the scan never discovers anything.</p>
  
  <p>Even though the services are running (I can communicate w/ them upon connecting), when I scan passing the service UUID array as <code>nil</code> and this delegate method is called...</p>
  
  <pre><code>-(void) centralManager:(CBCentralManager *)central 
   didDiscoverPeripheral:(CBPeripheral *)peripheral 
       advertisementData:(NSDictionary *)advertisementData 
                    RSSI:(NSNumber *)RSSI {
      DEBUG_LOG(@"Found peripheral w/ UUID: %@ RSSI: %@ \n AdvData: %@",peripheral.UUID,RSSI,advertisementData);
      DEBUG_LOG(@"Services found: %d",peripheral.services.count);
      for (CBService * service in peripheral.services) {
          DEBUG_LOG(@"Found service: %@ w/ UUID %@",service, service.UUID);
      }
  }
  </code></pre>
  
  <p>…it always reports "Services found: 0". Should I expect the <code>services</code> array to be populated w/ services found during the scan? (I assume this is at least partially possible, based on <code>scanForPeripheralsWithServices:[NSArray arrayWithObject:uuid]
                                              options:nil</code>.)</p>
  
  <p>Could this be a problem w/ my peripheral's service advertisements? Am I using the API incorrectly? Any guidance is much appreciated! :-)</p>
  
  <p>PS: I'm pretty green w/ Bluetooth.</p>
  
  <p>PPS: I control the source to the peripheral (it's a CC2540DK). So I'd be as likely to believe the problem is there as it is here.</p>