[TheMilkCarton]

You could try

<if condition="$show['member']">
is member
<else />
is not member
</if>

or

<if condition="$show['guest']">
is not member
<else />
is member
</if>

I'm not sure if you can use those variables in all templates, though.

Not sure why your code isn't working. I'm tired though.

You could also try this:

<if condition="is_member_of($bbuserinfo, 2, 5, 6, 7)">
is member
<else />
<if condition="is_member_of($bbuserinfo, 1)">
is not member
</if>
</if>

It's redundant, but if the "is not member" code is still showing to members then something is wrong.