WordPress MU

I am not sure where I can add new theme

I put them in /wp-inst/wp-content/sitetemplates

And when I try to go to the Theme admin panel I get this:

Warning: extract(): First argument should be an array in /home/blogwp/public_html/wp-inst/wp-includes/functions.php on line 1813

Warning: load_template(/home/blogwp/public_html/wp-inst/wp-content/themes/default/header.php): failed to open stream: No such file or directory in /home/blogwp/public_html/wp-inst/wp-includes/functions.php on line 1815

Fatal error: load_template(): Failed opening required '/home/blogwp/public_html/wp-inst/wp-content/themes/default/header.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/blogwp/public_html/wp-inst/wp-includes/functions.php on line 1815

My website is http://www.blogwp.com

Hm, seems you tried to get wp themes running in wpmu.
That does'nt work.
WPMU uses the smarty templating system, which uses html templates.
You'll have to rewrite your wp themes

*cue drum roll* I'm looking into using WP themes as well as Smarty based WPMU themes. It's actually quite easy to provide them read-only - since the WP themes aren't copied from wp-content/themes/ we can't allow blog users permission to edit them. (They'd edit a particular theme and the edit would be propogated across all blogs on that host)
Allowing users the ability to edit them is harder as the files would have to be copied into wp-content/blogs/BLOGNAME/templates/ and WP code modified to cope with that.

Ok thanks - but where can I obtain smarty templates .. I only have one :(

Now that is a good drumroll! Shame about the not being able to edit them... but good for newbies!

Here are some themes: http://incsub.org/blog/index.php?page_id=320

thanks!