Custom CSS Classes not working

[Scribbller]

Ok I did this to my first style and it worked perfectly this is contents of forumhome_forumbit_level1_post template

<tbody>
	<tr align="center">
		<td class="alt3Active" colspan="2" align="$stylevar[left]" id="f$forum[forumid]">
		
		<table cellpadding="0" cellspacing="0" border="0">
		<tr>
			<td><img src="$stylevar[imgdir_statusicon]/forum_$forum[statusicon].gif" alt="" border="0" /></td>
			<td><img src="$vboptions[cleargifurl]" alt="" width="9" height="1" border="0" /></td>
			<td>
			<div>
				<a href="forumdisplay.php?$session[sessionurl]f=$forum[forumid]"><strong>$forum[title]</strong></a>
			</div>
			<if condition="$show['forumdescription']"><div class="smallfont">$forum[description]</div></if>
			<if condition="$show['forumsubscription']"><div class="smallfont"><strong><a href="subscription.php?$session[sessionurl]do=removesubscription&amp;f=$forum[forumid]">$vbphrase[unsubscribe_from_this_forum]</a></strong></div></if>
			<if condition="$show['subforums']"><div class="smallfont" style="margin-top:$stylevar[cellpadding]px"><strong>$vbphrase[subforums]</strong>: $forum[subforums]</div></if>
			</td>
		</tr>
		</table>
		
		</td>
		<td class="alt3" nowrap="nowrap">$forum[lastpostinfo]</td>
		<td class="alt3">$forum[threadcount]</td>
		<td class="alt3">$forum[replycount]</td>
		<if condition="$vboptions['showmoderatorcolumn']">
		<td class="alt3"><div class="smallfont">$forum[moderators]&nbsp;</div></td>
		</if>
	</tr>
</tbody>
<if condition="$childforumbits">
<tbody>
	$childforumbits
</tbody>
</if>

You will see that I introduced two new css classes namely alt3 and alt3Active and in the css styles I defined both of them at the bottom like this

.alt3 { background-color: #f7fff7; color: #000000; }
.alt3Active { background-color: #f7fff7; color: #000000;  }
.alt3 a:link { color: #000000; text-decoration: none; }
.alt3 a:visited { color: #000000; text-decoration: none; }
.alt3 a:hover, .thead a:active { color: #009900; text-decoration: none; }

Something has gone very strange though you will see that template refers to alt3 and alt3Active classes but its still not picking that up infact when you look at the source of the page it is still using alt2 and alt2Active classes which were orignally there in VB default style.

I am modifying default VB theme here.

Can anyone please help

Regards