How to phrase part of a conditional statement?

[kh99]

OK, I just tried this and it works (at least as far as being valid template syntax):

<vb:if condition="!in_array ($GLOBALS['forumid'], $GLOBALS['special_forums'])">
Stuff here
</vb:if>

So it's possible that you have something else wrong in the template. The second error does say something about "invalid tag nesting", so if you took out only the <vb:if ...> tag but not the corresponding </vb:if> then that might be why.