image field problem with FF

[departedmind]

While keeping input type image, other input box moves down and that image moves uo, how can we adjust them in same line ?

 

here is my code....

 

.rtCol input{ width:235px; height:32px; border:1px solid #3bc7f2; margin:0; padding:0}
.rtCol input.small{ width:100px; height:32px;}
.rtCol input.btn{ width:60px; height:34px;}
.rtCol select{ width:65px; height:34px; border:1px solid #3bc7f2; margin:0; padding:0; _font-size:25px;}

<table width="100%" border="0" cellspacing="0" cellpadding="0">
            <tr>
              <td width="38%"><input type="text" name="textfield" id="textfield" /></td>
              <td width="10%"><select name="">
                </select>
              </td>
              <td width="16%"><input type="text" name="textfield" id="textfield" class="small" /></td>
              <td width="36%"><input name="input" type="image" src="images/search.png" class="btn" /></td>
            </tr>
            <tr>
              <td>Eg. a keyword like <a href="#">Television</a> or <a href="#">Plumber</a> </td>
              <td>Eg.<a href="#">NSW</a>, </td>
              <td><a href="#">Sydney</a> or <a href="#">2000</a></td>
              <td> </td>
            </tr>
            <tr>
              <td></td>
              <td> </td>
              <td> </td>
              <td align="right"><a href="#" class="advance">Advanced Search</a></td>
            </tr>
          </table>