Non-greedy regex behaves greedily

fourmi has asked for the wisdom of the Perl Monks concerning the following question:

s/<body.+?>/<body class="theBody">/is insists on changing

<body><!--msnavigation-->
[download]

<body class="theBody">
[download]

Any ideas why it is grabbing the comment aswell?

thanks
ant

2004-11-11 Edited by Arunbear: Changed title from 'Pattern Matching', as per Monastery guidelines