Wordpress Mu - bad url as images path

i successfully installed wordpress Mu in my subdomain, as a subdirectory install.

So now i successfully created some blogs having this address:


When i try to upload any media, i have a big problem.
The files are correctly uploaded in the right folder, eg:


BUT, the path of the image is set as:


This way any media i’ll try to upload will resoult in a broken link, a 404 error, so i can’t upload any image.

I activated the .htaccess i found in the installation folder, but it seems not working properly, nothing changes…

Anyone can help me?