BuddyPress.org

Tried..still no luck. But your comments are right.
When buddypress is inactive, I still have the same problem to go to blog posts and pages. That means core wordpress issue. It works with default setting, but doesn’t work with custom permalink setting. As most of the buddypress users have to use wordpress, does any one can point to me right settings ?

My WP & BP are installed in a sub-directory. I never had any problem until I testing the upgraded version.

Its is multi site (WPMU) installation but I only have one site. here is my .htaccess file

# BEGIN WordPress
# BEGIN ANTISPAMBLOG REGISTRATION
RewriteCond %{REQUEST_METHOD} POST
RewriteCond %{REQUEST_URI} .register*
RewriteCond %{HTTP_REFERER} !.*http://mywebsite.com/bp/.* [OR]
RewriteCond %{HTTP_USER_AGENT} ^$
RewriteRule (.*) http://die-spammers.com/ [R=301,L]
# END ANTISPAMBLOG REGISTRATION

# protect wpconfig.php

order allow,deny
deny from all

#uploaded files
RewriteRule ^(.*/)?files/$ index.php [L]
RewriteCond %{REQUEST_URI} !.*wp-content/plugins.*
RewriteRule ^(.*/)?files/(.*) wp-content/blogs.php?file=$2 [L]

# add a trailing slash to /wp-admin
RewriteCond %{REQUEST_URI} ^.*/wp-admin$
RewriteRule ^(.+)$ $1/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule . – [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-.*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*.php)$ $2 [L]
RewriteRule . index.php [L]

SecFilterEngine Off
SecFilterScanPOST Off

# END WordPress