Ok,

Your solpart menu will need these attributes added to it in the skin's ascx file:

rootmenuitemcssclass="rootmenuitem" rootmenuitemselectedcssclass="rootmenuitemselected" rootmenuitemactivecssclass="rootmenuitemactive"

Check that your menu hasn't already got these items specified. They may already be there, but they may have different name values specified.

Then add this to your stylesheet:

.rootmenuitemactive img,.rootMenuItem img,.rootmenuitemselected img{display:none}

Change the class names to match if your menu already had them specified as something else.

Rob

Okay, finally got it sorted out.

Just incase anyone is interested, here is what I did:

In my .ascx file, I used the following control:

<dnn:MENU runat="server" 
          ID="dnnMENU" 
          ControlOrientation="Vertical" 
          UseRootBreadCrumbArrow="false"  
          MenuItemCssClass="menuItem" 
          MenuItemSelCssClass="menuItemSelected"  
          MenuIconCssClass="menuItemIcon" 
          CSSIndicateChildRoot="menuItemArrow" 
          CSSIndicateChildSub="menuItemArrow"/>

And then in my skin.css file:

.menuItem
{
    background-color: #4D9EDC;
    border: none;
    font-family: Tahoma, Arial, Helvetica;
    font-size: 14px;
    font-weight:bold;
    color: #FFFFFF;
    cursor: hand;
}   
.menuItemSelected 
{
    background-color: #BFE9FF;
    font-family: Tahoma, Arial, Helvetica;
    font-size: 14px;
    font-weight:bold;
    color: #000000;
    cursor: hand;
}   

.menuItemIcon 
{
}
.menuItem img
{
    display: none;
}
.menuItemSelected img
{
    display: none;
}

.menuItemArrow img
{
    display: block;
}  

 In this way, I used the .menuItem and .menuItemSelected classes to hide (display:none) all of the images, then explitly used the .menuItemArrow img to override this for the arrows.

Seems to work just fine!