The default.ida thing is a worm from a few years ago. It's trying to exploit IIS (Microsoft's webserver implementation) webservers. I'm surprised that people still haven't cleaned that up. It's called code red (http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=code+red). Since westhost is running apache, there is nothing to worry about except for bandwidth usage.
I've had requests looking for /sumthin also. I don't know what it is.