Submenu will not show in ie7 (quirck mode)

Hi everyone,

I need help for this project of mine located at:
https://www.cspo.qc.ca/ecole/plateau

In quirk mode IE, my submenu does not show under menu : nos activités.

I believe it is due to quirk mode which does not read css :hover properly.

I search the internet high and low for hours for a css based solution, but found nothing.

Unfortunately the client is a primary school and their browsers are all equipped with that awful ie7 unupdated.

Can someone make my day out there?

Here’s the list code I am using:

nav li:hover a{
    background-color: #EBDB24;
    font-size: large;
    border: solid 1pt white;
}

#nav ul.dropdown ul li {

width:250px; /* specify the width. */
margin-bottom: 0px;
margin-top: 0px;
padding: 0px;
margin-left: 20px;
border: solid thin white;
}

/* Hide all the dropdowns (submenus) */
ul.dropdown ul,
ul.dropdown li:hover ul,
ul.dropdown ul li:hover ul
{ display: none;
}

/* Display the submenus only when li are hovered */

ul.dropdown li:hover ul,
ul.dropdown ul li:hover ul,
ul.dropdown ul li ul li:hover ul
{ display: block;
}

#nav ul.dropdown ul li:hover a
{
 background-color: #31396A;
}

Anxiously standing by…