I couldn’t figure out why osCommerce would print a default heading title (HEADING_TITLE) as the category page titles. In order to use the category name as the page title with osCommerce I had to edit the main index.php file. Find the lines which prints the category and nested category titles in and around line 68 and 233. You can look for the language definition: HEADING_TITLE.
Replace this with data from the breadcrumb array. So, basically, replace this line:
< ? php echo HEADING_TITLE; ?>
With this line:
< ? php echo $breadcrumb->_trail[end(array_keys($breadcrumb->_trail))][‘title’]; ?>
Basically what this does is take the title element of the breadcrumb->_trail object and prints it. There’s two places in the index file where this will need to be used. One is for main category listings and the other is for sub category listings. The single echo above should do it.
This may prove to be a bad hack and will need updating by me later on, but for now, this is the way I was able to use the category name as the title for my osCommerce installation.