Help! My .htaccess file has stopped working!

Friends,
I have set up my .htaccess file on an Apache 1.3.34 server with several redirects and rewrites, but strangely it has stopped working and I haven't got a clue why. I would like to permanently redirect all visitors to the English homepage (en/index.htm) of the multilingual website, but I would like that page to be rewritten to en/. Something went wrong along the way and currently the English homepage is shown as the root directory (/ instead of /en/) and when you click on the link to the English homepage, you see an "index of" page. And there's an old index.html file with some backlinks that I would like to 301 redirect to en/ too. Strangely, the 301 redirect to the www version does still work. Here's what I've got:

Options +Indexes
Options +FollowSymlinks
RewriteEngine on
RewriteBase /
RewriteCond %{HTTP_HOST} ^mydomain.tld [NC]
RewriteRule ^(.*)$ http://www.mydomain.tld/$1 [R=301,L]

DirectoryIndex [COLOR="Red"]index.html[/COLOR] [COLOR="Blue"]en/[/COLOR][COLOR="Green"]index.htm[/COLOR]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*[COLOR="Red"]index.html[/COLOR]\ HTTP/
RewriteRule ^[COLOR="Red"]index.html[/COLOR] [COLOR="Blue"]en/[/COLOR]$1 [R=301,NC,L]

RewriteCond %{THE_REQUEST} ^[A-Z]{3,9}\ /.*[COLOR="Green"]index.htm[/COLOR]\ HTTP/
RewriteRule ^[COLOR="Blue"]en/[/COLOR][COLOR="Green"]index.htm[/COLOR] [COLOR="Blue"]en/[/COLOR]$1 [R=301,NC,L]

ErrorDocument 404 http://www.mydomain.tld/error404.htm

Code (markup):

Can anyone help me out, please?

Thanks!

 

u have full root acess on ur server?