Solaris 10, ipfilter rdr rules and virtual interfaces

Hello,
I'm not terribly experienced with ipfilter, or Solaris for that matter,
and have a problem for which I've been unable to find a solution using
my usual resources (FAQ, google web, google groups, google some more).

I'm trying to configure an rdr rule for packets received on a virtual
interface (ce0:1), but the ipnat command fails, complaining about the
interface name. This appears to be valid because the grammar provided in
the ipnat.conf man page suggests ifname must match:
[a-zA-Z][a-zA-Z]*[0-9]. Clear virtual interfaces names don't.

ipnat.conf:
#
rdr ce0:1 0.0.0.0/0 port 3891 -> 127.0.0.1 port 389

# ipnat -f /etc/ipf/ipnat.conf
syntax error error at ":", line 2

What am I doing wrong? Is there something else I should be doing?

regards
Terry

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Terry Dawson
Solution Architect, Elanti Systems Inc.