I need scrollable header for tables. So I decided to use postion: fixed on styles. The problem is the width is shrinked on Firefox & Chrome. It works fine on Mozilla. For your reference I posted my HTML table code.
<html>
<head>
</head>
<body>
<table width="150%">
<thead>
<tr>
<th width="50%" align="left">Head 1</th>
<th width="50%" align="left">Head 2</th>
</tr>
</thead>
<tbody>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
<tr>
<td>Value 1</td>
<td>Value 2</td>
</tr>
</tbody>
<tfoot>
<tr><td>Foot 1</td></tr>
</tfoot>
</table>
</body>
</html>