WordPress MU

i have problem with uploading files. The uploading system is work well, but it can not display the file(such as picture),. i think the problem is comes from the .HTACCESS.
the following two lines are relate to the files:
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RewriteRule ^([_0-9a-zA-Z-]+)/files/(.*) /wp-inst/wp-content/blogs.php?file=$1 [L]
RewriteRule ^([_0-9a-zA-Z-]+)/wp-content/blogs/(.*)/files/(.*) /wp-inst/wp-content/blogs.php?file=$3 [L]
--------------------

How to correct this?
thanks

are you running a vhost installation or a non-vhost?

what is vhost? i do not know.

i got it fixed at :
http://mu.wordpress.org/forums/topic.php?id=1138&replies=3
thank you