HTML5 and CSS - Something must be wrong with my rowspan and colspan - css

Question

This is supposed to be a sudoku table. I checked the css elements and everything appears to be in good working order. I think that I made mistakes in the colspan and rowspan in the table. The "greenBox and "goldBox" classes should make the background images span across 3 rows and 3 columns; however, in the sudoku 9x9 table only 9 squares are filled with the background images. Any help is greatly appreciated. Thank you for your time.
<table class="spuzzle">
<caption>Sudoku</caption>
<thead>
<tr>
<th> </th>
<th>1</th>
<th>2</th>
<th>3</th>
<th>4</th>
<th>5</th>
<th>6</th>
<th>7</th>
<th>8</th>
<th>9</th>
</tr>
</thead>
<tbody>
<tr>
<th>A</th>
<td class="greenBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td> </td>
<td> </td>
<td>4</td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>3</td>
<td>5</td>
<td> </td>
</tr>
</table>
</td>
<td class="goldBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td>5</td>
<td> </td>
<td>3</td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
</table>
</td>
<td class="greenBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td> </td>
<td>7</td>
<td> </td>
</tr>
<tr>
<td>3</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>2</td>
<td> </td>
<td> </td>
</tr>
</table>
</td>
</tr>
<tr>
<th>B</th>
</tr>
<tr>
<th>C</th>
</tr>
<tr>
<th>D</th>
<td class="goldBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>6</td>
<td> </td>
<td>9</td>
</tr>
<tr>
<td>4</td>
<td>7</td>
<td>2</td>
</tr>
</table>
</td>
<td class="greenBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td> </td>
<td>2</td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td>9</td>
<td> </td>
</tr>
</table>
</td>
<td class="goldBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td>9</td>
<td>3</td>
<td>7</td>
</tr>
<tr>
<td>4</td>
<td> </td>
<td>8</td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
</table>
</td>
</tr>
<tr>
<th>E</th>
</tr>
<tr>
<th>F</th>
</tr>
<tr>
<th>G</th>
<td class="greenBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td> </td>
<td> </td>
<td>1</td>
</tr>
<tr>
<td> </td>
<td>4</td>
<td>5</td>
</tr>
<tr>
<td> </td>
<td>6</td>
<td> </td>
</tr>
</table>
</td>
<td class="goldBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>8</td>
<td> </td>
<td>1</td>
</tr>
</table>
</td>
<td class="greenBox" rowspan="3" colspan="3">
<table class="subTable">
<tr>
<td> </td>
<td>5</td>
<td>2</td>
</tr>
<tr>
<td> </td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>7</td>
<td> </td>
<td> </td>
</tr>
</table>
</td>
</tr>
<tr>
<th>H</th>
</tr>
<tr>
<th>I</th>
</tr>
</tbody>
`
</table>
The CSS is posted below. But I believe that it's functioning as it should.
table.spuzzle
{
border-collapse:collapse;
}
table.subTable
{
border-collapse:collapse;
}
table.spuzzle td
{
border:5px outset gray;
}
table.spuzzle th
{
font-size:8px;
color:gray;
}
tbody th
{
height:40px;
}
table.subTable td
{
font-size:20px;
color:blue;
width:40px;
height:40px;
text-align:center;
vertical-align:middle;
border:1px solid black;
}
td.goldBox
{
background-image:url("gold.jpg");
background-position:center center;
background-repeat:no-repeat;
}
td.greenBox
{
background-image:url("green.jpg");
background-position:center center;
background-repeat:no-repeat;
}

Answer 1

It appears your background images aren't large enough.
Try replacing images with background color to see if the basic affect is right then, look at what is going wrong with the images, perhaps remove background-repeat:no-repeat;. See http://jsfiddle.net/d6ZNF/1/ for using solid colors.
When debugging, also keep in mind that CSS is case-sensitive. I also recommend using a tool like Firebug for Firefox (free download) or developer tools in Chrome (hit F12) to inspect the suspect elements and see what, if any, CSS classes are applied to them.