Airport express - upgrading to firmware 7.3.2 but failing

I've been trying to get one of my airport express n units to upgrade to firmware 7.3.2 and am having problems. The unit works fine for it's normal function - printing - but refuses to upgrade firmware. Every time I try, the utility times out. Also, Airport Utility cannot read the configuration of the unit and the reset button refuses to reset the unit. The location of the unit does not seem to matter, as I've tried several. What gives?