i've the next problem:

Around the download dialog on each browser it shows me just the us dot extension filename like .divx

However i want the entire title eg

http://example.com/14558/.divx rewrites to 14558.divx and never onyly .divx

I would like see on every browser dialog the amount and also the extension. like 14558.divx

The way i can solve this issue ??

RewriteRule ^([0-9]+)/.divx$ $1.divx
RewriteRule ^([0-9]+)/.mkv$ $1.mkv
RewriteRule ^([0-9]+)/.avi$ $1.avi

Current Configuration:
RewriteRule ^([0-9]+)/\.(divx|mkv|avi)$ /$1.$2

Rewrite Log:
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae5c7c8/initial] (3) [perdir F:/media/video_files/] add path info postfix: F:/media/video_files/29 -> F:/media/video_files/29/.mkv
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae5c7c8/initial] (3) [perdir F:/media/video_files/] strip per-dir prefix: F:/media/video_files/29/.mkv -> 29/.mkv
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae5c7c8/initial] (3) [perdir F:/media/video_files/] applying pattern '^([0-9]+)/\.(divx|mkv|avi)$' to uri '29/.mkv'
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae5c7c8/initial] (2) [perdir F:/media/video_files/] rewrite '29/.mkv' -> '/29.mkv'
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae5c7c8/initial] (1) [perdir F:/media/video_files/] internal redirect with /29.mkv [INTERNAL REDIRECT]
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae588f8/initial/redir#1] (3) [perdir F:/media/video_files/] strip per-dir prefix: F:/media/video_files/29.mkv -> 29.mkv
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae588f8/initial/redir#1] (3) [perdir F:/media/video_files/] applying pattern '^([0-9]+)/\.(divx|mkv|avi)$' to uri '29.mkv'
127.0.0.1 - - [19/Dec/2011:13:07:02 +0100] [video.local/sid#4518f8][rid#ae588f8/initial/redir#1] (1) [perdir F:/media/video_files/] pass through F:/media/video_files/29.mkv

Your rewriterules appear ok... err well it can be the backslash. Incidentally you can optimize inside a better way (not examined):

RewriteRule ^([0-9]+)/\.(divx|mkv|avi)$ /$1.$2

But the only method to solve your condition (= show the entire filename) is to create a full redirect to some URL which has the entire filename.

So inside your situation redirect means these rules:

RewriteRule ^([0-9]+)/\.(divx|mkv|avi)$ $1.$2 [QSA,R=301,L]

Which suggests the Web addresses like "14558.divx" and "1526.mkv" need to be valid and return the file.

Two hints:

Please use the RewriteLog directive: it allows you to find such problems:

# Trace:
# (!) file gets big quickly, remove in prod environments:
RewriteLog "/web/logs/mywebsite.rewrite.log"
RewriteLogLevel 9
RewriteEngine On

My personal favorite tool to check on for regexp:

http://www.quanetic.com/Regex (be sure to choose ereg(POSIX) rather than preg(PCRE)!)