[Black Tiger]

I have 3.6 and had a look at the begin and end lines and they were exactly the same as in the guide.
This is exactly the same, start from here:
<if condition="$show['guest']">
<!-- guest welcome message -->
<tr>

And remove everything there with the below things as last lines:
<!-- / guest welcome message -->
</if>
That matches exactly the 3.6 template. So just remove in 3.6 the complete "if" condition of the guest welcome message from <if> till </if>, that should do the trick and worked fine on my 3.6 gold forum.