Clean URL on Drupal Multisite

Hi,

I have installed drupal6.17 on a subdirectory ( NOT on Root) like http://firstsite.com/drupal/,

then i created a new site applying multisite method i.e http://secondsite.com which runs normal.

Now my problem is the clean url works on http://firstsite.com/drupal/ but does not work with new site http://secondsite.com

the htaccess rewrite rule is used as original from drupal

Rewrite URLs of the form ‘x’ to the form ‘index.php?q=x’.
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !=/favicon.ico
RewriteRule ^(.*)$ index.php?q=$1 [L,QSA]

when i use with a slash like below, then it works with secondsite, but fails on firstsite.

RewriteRule ^(.*)$ /index.php?q=$1 [L,QSA]

Also i tried with

RewriteRule ^(.*)/$ index.php?q=$1 [L,QSA] which not working on 2nd site.

Any suggestion will be grate help!