.DescartesToolBar .DescartesButtonContentTaskAddGroupItemInactive {
    background: url("img/add_group_disabled.gif") no-repeat center;
    float:left;
}
.DescartesToolBar .DescartesButtonContentTaskAddGroupItemActive {
    background: url("img/add_group_enabled.gif") no-repeat center;
    float:left;
}
.vakata-context .DescartesButtonContentTaskAddGroupContextMenu {
    background: url("img/add_group_enabled.gif") no-repeat center;
}