Smoothie, I found a fix for this for the Quick reply Box if you still need it. If you have Logician's Dynamic Templates hack installed, all you need to do is this:
PHP Code:
[[($forum[forumallowattach]==1)]]
<tr>
<td bgcolor="{secondaltcolor}" valign="top"><normalfont><b>Attach file:</b></normalfont><br>
<smallfont>Maximum size: $maxattachsize bytes</smallfont></td>
<td bgcolor="{secondaltcolor}" valign="top"><smallfont><input type="hidden" name="MAX_FILE_SIZE" value="$maxattachsize_temp">
<input type="file" class="bginput" name="attachment" size="$textareacols"><br>
Valid file extensions: $attachextensions</smallfont></td>
</tr>
[[/($forum[forumallowattach]==1)]]
If you don't, let me know and I will supply the php work-a-round.
NOTE: The code for my attachments is a little different than yours. Just use the opening and closing [[($forum[forumallowattach]==1)]] tags on yours.