I got it to work... placing the answer here in case anyone else is
having a similar issue.
1- verifyNotVisible(submenu element's XPath) - verifies the submenu is
not visible when the page loads (useful to prevent false-positives in
case the later test to verify it is visible)
2- mouseOver(mainmenu element's XPath) - mouse over to the heading in
the menu you want to hover over
3- mouseMove(mainmenu element's XPath) - move the mouse at the same
location as step 2
4- waitForVisible(submenu element's XPath) - wait for the submenu to
appear
<tr>
<td>verifyNotVisible</td>
<td>//html/body/div/div/div/ul[2]/li/ul/li</td>
<td></td>
</tr>
<tr>
<td>mouseOver</td>
<td>//html/body/div/div/div/ul[2]/li/a</td>
<td></td>
</tr>
<tr>
<td>mouseMove</td>
<td>//html/body/div/div/div/ul[2]/li/a</td>