RewriteCond not evaluated for backhanded pages?

Ok, I'm confused here. I'm trying to use mod_rewrite to migrate an old
domain name to a new one... so I have this:

RewriteCond %{HTTP_HOST} abc.defg.com
RewriteRule ^/(.*) http://new.hostname.com/$1 [R,L]

This works for all pages not backhanded. Anything that is backhanded
gets shown to mod_rewrite as a 'subreq', and no RewriteConds seem to be
evaluated (other rewrite rules are eval'd).

We currently use a setup like so:

<Location /js.php>
    AllowOverride None
    Options None
    Order allow,deny
    Allow from all
    Backhand byAge 6
    BackhandFromSO libexec/byHostname.so byHostname (js)
    Backhand byRandom
    Backhand byLogWindow
    Backhand byLoad
</Location>

So requests for x.php never hit the RewriteCond. I get entries like this
in the rewrite log (RewriteLogLevel is 5):

x.x.x.x - - [26/Mar/2004:13:06:50 -0800]
[lhh.careercast.com/sid#810eb34][rid#8120414/subreq] (2) init rewrite
engine with requested uri /js.php
x.x.x.x - - [26/Mar/2004:13:06:50 -0800]
[lhh.careercast.com/sid#810eb34][rid#8120414/subreq] (1) pass through
/js.php

Is there a reason for this? Am I crazy? We have found a workaround, but
it would be nice to have this ability.