LinuxQuestions.org - Apache2 CustomLog no output

Hello! Maybe some of you can help me
I have this in my apache2.conf. The pupose of the code is to not log any of the file formats I've set.

Code:

SetEnvIf Request_URI "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|gz|swf|txt)$" dontlog

  LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{cookie}i\" \"%{User-Agent}i\"" combined

  CustomLog /var/log/apache2/custom_access.log combined env=!dontlog

The pupose of the code is to not log any of the file formats I've set to help keep my log tidy (so I can analyze it with my program I'm going to create)
Basicly the log file is created but nothing is logged and is empty.
I've tested this out on Ubuntu + 8.04 Apache 2.2.8 And also Debian EEE Lenny + Apache 2.2.9. Both results being new log file but empty.

Any ideas as to why this is happening, is my code wrong?