Usually you would not have the same host name, this is probably causing a wierd infinite redirect kind of issue. In your case the web request is coming in with the Host: http header field set to "www.seriousmovers.com" Booster then lookups up the booster.config file to find what it maps to and finds "www.seriousmowers.com". Booster then opens a socket connection to that host to begin the transaction. If this resolves to the same (Booster) server, then booster will open a connection to itself and start the process again. 

Probably go for something like: 

HOSTS~www.seriousmowers.com=internal.seriousmowers.com

or (if the http server is on the same box as booster)

HOSTS~www.seriousmowers.com=www.seriousmowers.com:9000