[fbastello]

OK, I think I cracked it
Basically, I added the following line just before return "<!-- BEGIN ad {$adcomment} -->{$ad['html']}<!-- END ad {$adid} -->";
in the view_ad function plugin:
$phpAds_context[] = array('!=' => 'bannerid:'.$ad['bannerid']);

This basically will allow you to have several <ad what="zone:1" /> anywhere in your templates and be sure that the same banner is not displayed twice.

I've just done it so it's not quite well tested yet, I'm sure that the whole thing could be improved via the ad tag (something like <ad what="zone:1" duplicate_banner_id="1" /> or <ad what="zone:1" duplicate_banner_id="0" /> to switch the option on or off).

Hope this help and thanks again for this great plugin!
F