non-glue record error (can't figure it out)

[loren jan wilson]

so, i installed 8.2.3 because 9.1.0 was too flaky.
here, though, a different problem--

on the primary nameserver, we got this error:
Feb  4 21:55:12 ns1 named[16645]: zone: uchicago.edu/IN: non-glue
record below bottom of zone: uhs.mcis.uchicago.edu/CNAME

here's the offending record:
uhs.mcis       in      cname   uhs.bsd

for some reason, though, these similar records don't cause error:
uhrm.training   in      cname   krypton
uhs-scrs        in      cname   uhs.bsd

to get the nameserver to load the file, i had to comment out the
uhs.mcis entry. 
what can i do to get it back? why does it happen on only one of the
above three?

thanks,
loren