I've tried centering it in a table a div and hard coded the center around the menu itself but still it stays left aligned.

I've also cleared my cache, etc to see if it was that, but still nothing.

Is there any way at all I can center the SolPart menu?

Yep, I've got it in a table, and I think I've solved the moving problem in IE, (still the same in FF and Opera). The other problem I'm having is with the buttons, when thye're clicked, they indent, is there a way to switch that off or is that something I've done?

Finally,
Is it possible to switch of the SolPart's Breadcrumb?

The CSS I'm using is:

.MainMenu_MenuContainer {
    background-color: transparent;
    text-align: center;
}
.MainMenu_MenuBar {
    cursor: pointer;
    cursor: hand;
    height:16px;
    background-color: Transparent;
}
.MainMenu_MenuItem {
    border-left: 0px;
    border-bottom: 0px;
    border-top: 0px;
    border-right: 0px;
    cursor: pointer;
    cursor: hand;
    color: #0065AC;
    font-size: 10px;
    font-weight: bold;
    font-style: normal;
    background-color: transparent;
    font-family: verdana, sans-serif;
}
.MainMenu_MenuIcon {
    background-color: transparent;
    border-left: transparent;
    border-bottom: transparent;
    border-top: transparent;
    cursor: pointer;
    cursor: hand;
    text-align: center;
    width: 15px;
    height: 21px;
}
.MainMenu_SubMenu {
    background-color: #D4E6F4;
    z-index: 1000;
    cursor: pointer;
    cursor: hand;
}
.MainMenu_MenuBreak {
    height: 1px;
}
.MainMenu_MenuItemSel {
    background-color: transparent;
    cursor: pointer;
    cursor: hand;
    color: #F97D35;
    font-family: verdana, sans-serif;
    font-size: 10px;
    font-weight: bold;
    font-style: normal;
    /*height: 21px;*/ <-- This line is commented out, because it was what I had found to be causing the moving nav problem.
}
.MainMenu_MenuArrow {
    border-right: #cad5ea 1px solid;
    border-bottom: #cad5ea 1px solid;
    border-top: #cad5ea 0px solid;
    font-family: webdings;
    font-size: 10px;
    cursor: pointer;
    cursor: hand;
}
.MainMenu_RootMenuArrow {
    font-family: webdings;
    font-size: 10px;
    cursor: pointer;
    cursor: hand;
}

As you can see, its not all been changed, mainly just colors.

So I can't see what's up to be honest.