We both are using VB3 enhanced so there are no $pimgtag[$x] or $prodimgtag[$x] in feature.tmpl
Umm.. a novice question... why the problem would be in feature.tmpl? I've a feeling that the problem would be in showcat.tmpl and probably here:
line 40 ->
echo<<<PPPRINT
<tr>
<td class="{$gallery['rowcolor'][$x]}" width="15" align="center">
PPPRINT;
$mthumb = $gallery['hasimage'][$x];
include( "{$Globals['PP_PATH']}/templates/thumbnail.tmpl" );
echo<<<PPPRINT
or then in showcat.php
Because for example if you go here (I'm borrowing this from your site DertyLee

)
http://www.makemusic.gr/classifieds/showcat.php?cat=2
you'll see no thumbnails there in front of product line (just an empty cell) even though that test2 product has one
http://www.makemusic.gr/classifieds/...1&cat=2&page=1