Working PHP/MySQL block breaks in 3.2.1

I’m setting up a WP site for a computer services company, and they need a work order form. I’m setting it up as a page, and the relevant tables are in the same database as the WP install. I’m using Grimp’s PHP plugin to run the code. The code block is as follows:

$query = "SELECT * FROM techs WHERE 1";
$q = mysql_query($query) or die(mysql_error()); ?>
<select name="tech">
<?php while($row = mysql_fetch_assoc($q)) { ?>
<option value="<?php echo $row['TechID']; ?>"><?php echo $row['techname']; ?></option><?php } ?>
</select>

It works on it’s own (here), but when I use the same code block on a WP page I get outward-facing HTML like so:

<select name='tech'>
<option value="">
</option>
</select>

When I echo $q I get a resource link identifier, and even doing mysql_num_rows in an echo gives the correct result. So I’m at a loss as to why the code is breaking. Any help would be appreciated.