Macbook sometimes drops my wifi connection and can't reconnect for a few minutes
If you were to run the Wireless Diagnostic tool each time the network dropped, you might be able to look over the logs once you have 5 to 10 events and see if you can determine a pattern. It's hidden in the folder /System/Library/CoreServices/ and also available if you hold the option key and click on the wireless icon in the menu bar.

Once the tool runs and deposits the diagnostic data on your desktop - you might run it a second time and use the Utilities window to see if you can see interference or other issues on the Performance view.



That section where the noise jumped up was when I turned on our Microwave.