Forwarding RealAudio thru 2.2.19 firewall?

[Scott Bigham <dsb@killerbunnies.org>]

Are there known issues with forwarding/masquerading RealAudio
connections through a 2.2.19 kernel?  I upgraded my firewall box from
2.2.17 to 2.2.19 not long ago, and later noticed that machines on the
LAN were unable to connect to RealAudio servers.  Once I realized that
the two happened at around the same time, I rebooted back into 2.2.17 to
check, and it started working again.

I've checked everything I know to check; lsmod confirms that the
ip_masq_raudio module is loaded, and ipchains -L input -M seems to
indicate that the kernel is at least trying to forward the connection.
The two kernels are configured essentially the same; the only net-related
differences I can find are that in the 2.2.19 kernel, IPv6 is included
(as a module, which doesn't show up in lsmod) and IP-over-IP tunneling is
built-in instead of a module.  I even went so far as to put a -l on the
ipchains ACCEPT rules for UDP ports 6970:7170, and AFAICT no packets are
even coming in on those ports during a RealAudio connection attempt.

I'm at wit's end here.  Am I missing something obvious?

						-sbigham