Question: When I try to add Module Class Suffix to the menu module, it's not being shown on site.

I placed a custom value into the 'Module Class Suffix' field. There is only one menu component being used. However, the value I specified is not being appended to the classname attribute of the element.

I have cache disabled. Is there anything else I should check for? 

I'm using latest stable Joomla 3.0.2

Answer: 
I cannot vote up, yet - but Mike's comment to his own answer is the solution that is IMO missing from the standard joomla templates (e.g. beez or protostar). Thank you!
To clarify: I copied /modules/mod\_menu/tmpl/default.php to my template's html/mod\_menu/ directory and added the following near the top:

`<?php $moduleclass_sfx = htmlspecialchars($params->get('moduleclass_sfx')); ?>
 <nav class="navigation<?php echo $moduleclass_sfx; ?>">`

Right before the

`<?php // The menu class is deprecated. Use nav instead. ?>`

Of course, closed the `<nav>` at the end of the file, too.

(Almost missed the comment, that's why I wanted to vote and now had to post.)
Maybe the Module Template is not using the class suffix parameter.
In the template file of your module there should be something like:

```
<div class="mymodule<?php echo $moduleclass_sfx ?>">

```