header problems

[crazymilk]

I`m getting this fatal error on my admin cp when i try to change the header when it is all ready working all i`m doing is change the gif ? any help would be great.

Here is the error--

Fatal error: Call to undefined method vb_activecache::flush() in /home/www/blackops-squad.com/forums/includes/adminfunctions_template.php(2359) : eval()'d code on line 6

And here is the header that is all ready working all i`m doing is change LOGO5 to LOGO6 with same code ----

<table border="0" width="$stylevar[outertablewidth]" cellpadding="0" cellspacing="0" align="center" style="background-image:url(http://www.blackops-squad.com/bg-01.gif)">
<tr>

<td align="center"><a href="$vboptions[forumhome].php$session[sessionurl_q]"><img src="http://www.blackops-squad.com/maxjay/LOGO5.gif" border="0" alt="$vboptions[bbtitle]" /></a></td>

<td align="$stylevar[right]" id="header_right_cell">
<if condition="$ad_location['ad_header_logo']">$ad_location[ad_header_logo]<else />&nbsp;</if>
</td>

</tr>
</table>

Cheers