Rollover - obrazkowe menu jako lista - Problem

[Kartofelek]

Kod:

<a href="" class="ir img">Obrazek sraczek</a>

<style type="text/css">
.img {
     background:url(obrazek.png); width:100px; height:20px;
}
.img:hover {
     background-position:0 -20px;
}

.ir {
     font: 0/0 a !important;
     text-shadow: none !important;
     color: transparent !important;
     border:0 !important;
     background-color:transparent !important;
     display:inline-block;
     background-repeat:no-repeat;
}
</style>