Problema con el Width en FireFox

[aeayala]

Estoy contruyendo un control en el cual uno puede seleccionar un letra, y en base a esa letra (que es un Link) me muestra algo, bueno la cosa esta en que le puse un Background al hover del link y no toma el ancho de imagen sino el de la fuente el FireFox, en el IE6 se ve perfecto.
Si alguien me puede ayudar se lo agradeceria muchisimo .

aca les muestro el div, y mas a bajo los css.

Código HTML:

<div id="ByNameTitleContainer">
	<h2>Dog Breeds By Name</h2>
	<div id="BreedByName">
	<span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">A</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">B</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">C</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">D</span>
	<span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">E</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">F</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">G</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">H</span>
	<span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">I</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">J</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">K</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">L</span>
	<span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">M</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">N</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">O</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">P</span>
	<span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">Q</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">R</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">S</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">T</span>
	<span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">U</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">V</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">W</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">X</span>
	<span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">Y</span><span class="Alphabetic" onMouseOver="this.className='AlphabeticOn'" onMouseOut="this.className='Alphabetic'">Z</span>
	</div>
</div> 

Código HTML:

#ByNameTitleContainer {
	width: 736px;
	height:auto;
	position: relative;
	top:0px;
	left:0px;
	text-align: left;
	background-color: #FFFFFF;
}
#ByNameTitleContainer h2{
	font-family: Arial;
	font-size: 20px;
	font-weight: bold;
	line-height:100%;
	color:#8B3827;
	text-align: left;
	text-decoration:none;
	height: 43px;
	margin-top: 17px;
	margin-right: 0px;
	margin-left: 0px;
	margin-bottom: 0px;
}
#BreedByName {
	width: 100%;
	height: 21px;
	border-bottom-color: #DFB462;
	border-bottom-style: solid;
	border-bottom-width: 1px;
	border-top-color: #DFB462;
	border-top-style:solid;
	border-top-width: 1px;
	text-align: center;
}
#BreedByName span.Alphabetic{
	font-family: Verdana;
	font-size: 12px;
	font-weight: normal;
	line-height: 120%;
	color:#662428;
	text-align: center;
	background-image: url(../i/ucBreedByNameOff.jpg);
	width: 17px;
	height:15px;
	margin-left: 6px;
	margin-right: 6px;
	margin-bottom: 0px;
	margin-top:1px;
	display: inline;
	cursor: pointer;
	word-spacing: 2px;
	text-decoration: none;
}
#BreedByName span.AlphabeticOn{
	font-family: Verdana;
	font-size: 12px;
	font-weight: bold;
	line-height: 120%;
	color:#FFFFFF;
	text-align: center;
	background-image: url(../i/ucBreedByNameOn.jpg);
	width: 17px;
	height:15px;
	margin-left: 6px;
	margin-right: 6px;
	margin-bottom: 0px;
	margin-top:1px;
	display: inline;
	cursor: pointer;
	word-spacing: 2px;
	text-decoration: none;
}

#BreedByName a.Alphabetic:hover{
	font-weight: bold;
	line-height: 120%;
	color:#FFFFFF;
	background-image: url(../I/ucBreedByNameOn.jpg);
}