No, wait... It seems that something went awry with the firewall on my Host PC somewhere along the way. I hope there isn't some bigger, malevolent problem I should be worrying about.
Anyway, I rebooted the Host PC (I really ought to do that more often) and ensured that the connection to the PXI was not firewalled. It seems to be working, at least for now. I'll be keeping an eye on it.
