[Adrian Schneider]

First one

PHP Code:

<if condition="$GLOBALS['FIRSTPOSTID']"> 


Note that the ! means NOT, so if a condition usually returns true, it will then return false (and vice versa)...

Same with your show guest one, removing it will reverse it.

If you want to do both...

<if condition="your_condition">
    HTML Code
<else />
    HTML CODE
</if>

I don't think that code is correct, you are missing the ==, also you should use is_member_of() because it checks secondary usergroups too (if you just want to do primary, by all means use yours.)

PHP Code:

<if condition="is_member_of($vbulletin->userinfo, 2) OR is_member_of($vbulletin->userinfo, 3) OR is_member_of($vbulletin->userinfo, 4)">
    ...
</if> 


Replace the ORs with ANDs if you want it displayed only if they are in all groups.