Uploading photos in multi site

I have multi site installed..I can upload photos in main site ..it is the subdomain sites that cannot upload photos.

and when I attempt to upload a photo it says > “Apricots-0601 tree2.jpg” has failed to upload due to an error

Unable to create directory /home/*****/public_html/wp-content/blogs.dir/3/files/2011/03. Is its parent directory writable by the server?”

I have changed permissions in blogs.dir ; upload.php ; options-media.php and a few others with no success….also checked google to see if I can find a solution.

Any ideas what I might be doing wrong…..default wordpress theme….no buddypress,no plugins activated….Dedicated server.. Thxs