RewriteEngine On
RewriteCond %(REQUEST_FILENAME) !-f
RewriteRule ^(.*[^/])$ /BG/$1/
RewriteCond %{REQUEST_URI} !index.php [NC]
RewriteCond %{REQUEST_URI} !/BG/css [NC]
RewriteRule ^(.*?)/(.*)/$ index.php?id=$1&sub=$2 [L]
> Main Idea was that a request for /BG/something/more gets first converted to /BG/something/more/ and then to
> /BG/index.php?id=something&sub=more
> However it sometimes either produces something along the lines of /BG/index.php?id=index.php
of course, index.php matches the (.*) in your second rule, adding that cond should do the trick
> Any help is appreciated ^^
welcome