The full error, as seen on my site:
Parse error: syntax error, unexpected T_STRING in /homepages/29/d314539915/htdocs/wp-content/plugins/poppy-videos/poppy-videos.php on line 274
I took a look at the line in question and couldn't find any obvious (to me) syntax errors, but I don't know how the Stagevu function is supposed to look.
$htmlcode ='<center><iframe style='overflow: hidden; border: 0; width: 480px; height: 326px' src='http://stagevu.com/embed?width=480&height=270&background=000&uid='.$matches[$m].'' scrolling='no'></iframe></center><br />';