In case anyone's interested in the status of legacy modules under XOOPS 2.3.2 and PHP5 and XHTML validation, my changes to get Stockquotes 0.1 to validate for CSS level 2 and XHTML 1.0 Transitional are summarized below. Note: Curl fix for fopen already had been done, as well as replacement of $HTTP_GET_VARS with $_GET and $HTTP_POST_VARS with $_POST for PHP5 compatibility.

stockquotes 0.1 module

blocks/stockbox.php

Ampersands in the $block['iframeurl'] declaration were cleaned up.

templates/blocks/stockbox_iframe.html

style="overflow: clip;" was changed to style="overflow: auto;" in the file.