I'm sat here, right next to my wifi router and the wifi status on my MBP is giving me an 11Mb Transmit Rate. I've turned off any fully disconnected our cordless landline phones, the microwave is not on and there's nothing else in the house that could be causing wifi interference. I just don't understand why the Transmit Rate would be so low sat when the MBP is sat 5cm from the wifi router. The RSSI is -45. No wonder I can't stream music to the Airport Express. Earlier in the conservatory I was getting 54MB Transmit Rate!! Wish I could figure this out.