Problem with using $GENERATE for reverse-lookup (PTRs)

[ray at doubleclick.net]

Hey BIND experts ...

I'm running BIND 8.2.2-P5, and some time ago decided to use the nice
$GENERATE feature for PTR records. In particular, I want to ensure
reverse-lookup for all IPs in say, 172.16.1.0/24 resolve to something
like "host-172-16-1-?.example.com". This worked fine until recently,
either due to some mistake in my reverse zone (or perhaps a bug in
BIND, maybe related to the size of the zonefile?). Now if I try to
lookup a PTR within one of the ranges handled by my $GENERATE entries
nothing is returned :(

Here is one of the $GENERATE entries in the reverse zone of interest:
$GENERATE 51-254 $.1.16.172.in-addr.arpa. PTR host-172-16-1-$.example.com.

The reason I've fully-qualified both the lhs and the rhs fields is
I'm using a single zonefile with symbolic links pointing to it for all
the *.in-addr.arpa. domains the server is authoritative for. When AXFR
is invoked via SIGHUP or due to refresh, the named process running
locally (on the primary/master server) disregards the unrelated
records as it builds the data structures for each symlinked zone (at
least this seems to work fine! :) For example:

/var/named/db.reverse
/var/named/db.10 -> /var/named/db.reverse
/var/named/db.172.16 -> /var/named/db.reverse
/var/named/db.192.168 -> /var/named/db.reverse

and in named.conf, I would specify db.10, db.172.16, or db.192.168

So I guess my question is, what could be breaking the $GENERATE
functionality, and is it related to my use of symlinks to "jam"
records for many domains into a single physical zonefile? Again, at
one point the $GENERATE stuff worked (when there was only a single
$GENERATE entry, maybe).

Thanks in advance for your insight ...

--
Ray