I am sure this will be something crazy obvious. But I can't see it.
In my sidebar i have a few link.
i just added one to the archive page. (it is in the same folder/dir as the other usual wp page (index, footer, header, sidbar...))
the link is
HTML Code:
<li><a href="index.php">Main</a></li>
<li><a href="/cakes/">the other</a></li>
<li><a href="archives.php">archives</a></li>
<li><a href="http://www.google.com">google</a></li>
the archive page is of course archives.php (also tried to rename as cakes.php just to test...)

I also tried to do as I have seen in another page w/an archive as

HTML Code:
<li><a href="/archives/">archives</a></li>
but always get a 404.
the index link works fine, the google links as well. but cakes and archives do not.
is there a function or wp standard I am missing please?