[BirdOPrey5]

Edit your postbit_legacy (or postbit) template...

find:

		<if condition="$post['replylink']">
			<a href="$post[replylink]" rel="nofollow"><img src="$stylevar[imgdir_button]/<if condition="$post['forwardlink']">reply_small<else />quote</if>.gif" alt="$vbphrase[reply_with_quote]" border="0" /></a>

and replace with:

		<if condition="$post['replylink'] AND !$post[islastshown]">
			<a href="$post[replylink]" rel="nofollow"><img src="$stylevar[imgdir_button]/<if condition="$post['forwardlink']">reply_small<else />quote</if>.gif" alt="$vbphrase[reply_with_quote]" border="0" /></a>

Basically add the AND !$post[islastshown] to the conditional, this will stop the quote button from displaying on the last post.