[Simon]

Right after you close the head tag you have this:

<base target=_blank>

If you want to keep that there you'll need to add target="_self" to the archive links. Or you can get rid of that base target code since it looks like all the other links already have target="target_blank" in them, which will open each one in the same new window named "target_blank." If you want a new blank window you need to use target="_blank" (or onclick="target='_blank';" if you want to validate for XHTML).

Btw...there's no DOCTYPE on the page.

HTH