WordPress MU

I really need some advice to debug a problem I have..

http://mysite.com/category/news gives a not found page (not my 404 but i guess a wordpress generated not found page )

http://mysite.com/category/news/item-1 works

I copyed a theme from a friend that worked for him he could see all posts from hissite.com/category/news

I tryed everything
- Permalinks are on default setting
- No category base is set
- Settings, reading has default settings ( first page = show posts )

I cannot get this to work.. how can i fix this?!
I just want to be able to list all my posts from a certain category when I do http://mysite.com/category/mycategory

I also removed all my posts ( its a new blog )
and recreated them assigning them to the correct category

my news category has 2 blog posts now
If I do edit posts then click view it shows the url as

mysite.com/2009/08/firstnewsitem

it also show "news" as the category on this page
but when clicked on this link I also get the not found page

My category link seems to work okay

Archives in the sidebar goes to
http://mysite.com//2009/08/

Listing everything from this month ( 1 post )

In my sidebar there is
Categories
news (1)

But when clicked on i get

Not Found
Sorry, but you are looking for something that isn't here.

Based on this code

<div id="content" class="narrowcolumn">
<h2 class="center">Not Found</h2>
<p class="center">Sorry, but you are looking for something that isn't here.</p>
<form method="get" id="searchform" action="http://demo.wielercontent.nl/">
<label class="hidden" for="s">Search for:</label>
<div><input type="text" value="" name="s" id="s" />
<input type="submit" id="searchsubmit" value="Search" />
</div>
</form>

Which is *not* in my template directory

Anyone knows what is happening here?

Even If I set permalinks to default ?cat=x I get the not found message

Help! please

Nobody?!

Please help me out on this else i have to drop WPMU :(

"Archives in the sidebar goes to
http://mysite.com//2009/08/"

Note the extra slash. When you installed, did you stick an extra slash in there?

Can you go to mysite.com/about/ and see the page?

mysite.com/about/ goes okay andrea
thx any suggestions on how to fix this?

Turn off all plugins, set the blog back to the default theme, check if you get the same issues. And try resaving the options on the permalinks page.

Thanks Andrea! I was having this issue as well and resaving the permalinks options fixed it. Is there any way to fix this bug permanently?

I noticed it happened when I added a user to a blog.

The devs are looking at it. hard to fix becasue we don't know what's causing it.

I'm having this problem as well

http://buylocalbuildafuture.com/blog/category/teaching-resources/

I have a parent category with a child category that each is set to. If you click on the post for each, it just rounds back to the full listing. I tried resetting the permalinks with no luck.

Any suggestions? Thanks!