You're missing code in the tables where you added that link. Tables should be structured like this:
HTML Code:
<table>
<tr>
<td>Menu Item</td>
</tr>
<tr>
<td>Menu Item</td>
</tr>
<tr>
<td>Menu Item</td>
</tr>
</table>
Every <tr> is a table row and should always have at least one <td>. In the Quick Links menu, you should never put more than one <td> in a <tr>.
Basically, all you should have done was add a new <tr><td></td></tr> to the Quick Links menu below whatever you wanted it to show up, and duplicated whatever class name your skin is using for the <td> blocks. By default that's usually
vbmenu_control, but some custom skins can use random names. Just look at the other <td>s to see what they use. The class gives it the proper formating.
Additionally, if you already knew that, make sure your tags are nested. Opening and closing tags should NOT overlap anywhere in the code.
Correct
Code:
<tr><td class="vbmenu_control">Menu Item</td></tr>
Incorrect
Code:
<tr><td class="vbmenu_control">Menu Item</tr></td>