Within the templates you don't need the { }

In the php files themselves you do.

God you guys come up with some convoluted solutions to this problem.

If you want to limit something to guests only then use

Like i said in the first place :p

No, your conditional is !is_member of (Not is member of). The original poster only wants to show the ads to one group only - the guests, so the conditional should be is_member_of

:)

Like i posted within my post though.

If someone doesn't know the ! operator makes it an inverse, should they really be playing with the code ;)