Support for multilanguage sites, Internationalization (I18N)

[tomkop]

Hello, i have

RewriteRule ^/?$ sk/ [R,L] # optional
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(sk|hu|cz|en)/(.*?/)?([A-Za-z0-9-]+)/?$ index.php?id=$3&lang=$1 [QSA,L]
RewriteRule ^(sk|hu|cz|en)/?$ index.php?lang=$1 [QSA,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule /?([A-Za-z0-9-]+)/?$ index.php?id=$1 [QSA,L]

in admin permalink
%language%/%parent%/%slug%/

but this line in rewrite is problem:
RewriteRule ^(sk|hu|cz|en)/(.*?/)?([A-Za-z0-9-]+)/?$ index.php?id=$3&lang=$1 [QSA,L]

500 Internal server error.
on the other server it works ..
is there any way to fix it otherwise?

url si http://domain.sk/prietokomery/sk/sortiment/
not http://domain.sk/sk/sortiment/
can be a problem?
thanx you