Can connect to XBMC via IP address but not hostname

I have two XBMC installations, one on a XP laptop and another on a Win7 desktop. I have the official remote installed on both an Android phone as well as an Ipad. For both of these I can connect fine to either instance of XBMC if I specify the IP address, however not if I specify the hostname. This is annoying in that my IP addresses are not fixed, so I have to check them every time I want to use the remote. I'm not sure if I'm specifying the hostname incorrectly, I've tried the following:

bluefly
BLUEFLY
Bluefly
\\bluefly

etc but none made any difference. If I do a "ping bluefly" from command line it replies fine.

I have come across a similar thread on the forum but there was no solution posted. Any ideas?