[Tigga]

This is what you should have for that template...

<tr valign="top">
<td bgcolor="#1C5780"><normalfont><b>Your User Name:</b></normalfont></td>
<td bgcolor="#1C5780"><normalfont><input type="text" class="bginput" name="username" value="$bbuserinfo[username]" size="25">
</normalfont>
<smallfont><a href="/forums/register.php?action=signup">Want to register?</a>
</smallfont></td>
</tr>
<tr valign="top">
<td bgcolor="#13486D"><normalfont><b>Your Password:</b></normalfont></td>
<td bgcolor="#13486D"><normalfont><input type="password" class="bginput" name="password" value="" size="25">
</normalfont>
<smallfont><a href="/forums/member.php?s=$session[sessionhash]&action=lostpw">Forgotten your password?</a>
</smallfont></td>
</tr>

As for the links at the top, those are all in your header template. My suggestion would be to edit the links in that template as well and add /forums/ in front of each link there as well.