@arriflex:
That is what I have done. It's certainly not a crucial situation for me, and I didn't know any better when I did it back in the 1.2 release when I first started with pfSense. That it worked then, and didn't now is the only reason I brought it up.
Thanks again, sorry to distract from more pressing matters.
Any chance you still have a config backup and a CD around for 1.2 that you could toss on a spare box and see what is different about its dhcpd.conf that caused it to work? (Perhaps they were quoted or put in some other way)
It may have been an older version of ISC-DHCPD that allowed it, but I suppose it's possible something else changed in how the config was written. There was about a two-year gap between 1.2 and 1.2.3.
As wallabybob pointed out, hostnames should start with a letter, so the numeric hostnames are invalid. But if that is the case then the GUI should also be rejecting those as invalid hostnames.