Help with couple of mod_redirect rules

[Jaffery]

Since, I just got rid of vbseo, now I am trying to deal with redirect as much as possible. Taking care of threads was easy however still urls like tags, attachments etc. remains.. so, I hope guys here may help me through with their wisdom in mod_rewrite rules .. regex

So, I am stuck on this.. wants to do following:

redirect:
domain.com/talk/tags/letter.html (letter is tag)

To

domain.com/talk/tags.php?tag=letter


I tried this

RewriteRule tags/([^/]+)\.html /tags.php?tag=$1 [L,R=301]

But its not working.

My forum is at :
domain.com/talk

And I am adding above rule in domain.com/talk/.htaccess with "RewriteBase /talk/" .
This is where I have added thread redirection code which works fine.