no tag archive

Hello.

I have a problem which is quite similar to:
http://wordpress.org/support/topic/135881?replies=27
but I can’t sort it out

I am using pretty-permalinks, and I run wordpress in directory ‘site’ but the index.php is in the root.
I have a tag-cloud it displays, but when you click a tag you get a 404.
If I select standard permalinks the tag refers to the archive.php, but still no posts display…

I would like to get the tag-cloud to really work and of course have the pretty perma-links. You can watch the problem at http://www.biki90.nl

thank you for thinking