Cannot view formatting

TTMCE seems to be working correctly, in that when I examine the body of a node in the database I see the formatting codes. However, when I view the node, these codes are stripped out. Is there a further step I need to take to have the formatting codes recognized? (I'm sure this is a real noob question).

My init script:

tinyMCE.init({
mode : "exact",
init_instance_callback : "resizeEditorBox",
theme : "advanced",
convert_urls : false,
plugins : "safari,pagebreak,style,searchreplace,contextmenu,paste,directionality,nonbreaking",
theme_advanced_buttons1 : "bold,italic,underline,|,cut,copy,paste,|,search,replace,|,bullist,numlist,|,outdent,indent,|,undo,redo,|,link,unlink,cleanup,help,|, fullscreen",
theme_advanced_buttons2 : "",
theme_advanced_buttons3 : "",
theme_advanced_buttons4 : "",
theme_advanced_toolbar_location : "top",
theme_advanced_toolbar_align : "left",
theme_advanced_statusbar_location : "bottom",
theme_advanced_resizing : true,
extended_valid_elements : "a[name|href|target|title|onclick],span[class|align|style]",
template_external_list_url : "example_template_list.js",
});

For example, text that is formatted as bold gets tagged thusly:

<span style="font-weight: bold;">Bold text</span>

...and span is included in the valid elements. This is how it's saved in the database too. When I view the node and view HTML source, the span tags are removed. I'm using the default theme (garland).

What am I missing?

Thanks!