Three extensions? Are you absolutely positive you know what you're doing?
Hm. Been around since 2003. I guess you do.
RewriteRule (.*)\.css$ $1\.css.jgz [L]
It may work, but it's inefficient. The leading (.*) means that the server captures everything in sight, and then has to backtrack until it can pick up the .css extension. And, since you're recycling the css, it can simplify to
RewriteRule ([^.]+\.css)$ $1.jgz [L]
AddType "text/css" .css.jgz
Ouch! What's a mod_mime directive doing squeezed between two mod_rewrite directives? Aren't the first two lines (using two different modules) redundant?
RewriteRule ^(chat) - [L]
The first two line works perfect,
but the last line dont work.
What is the last line intended to do? As written, it says "capture the element 'chat' if it's a top-level file or directory, don't do anything with it, and start mod_rewrite from the top". So if the Rule is intended to do nothing, I would have to say that it's working perfectly.
If you want the css-to-css.jpz stuff to happen everywhere
except in the /chat/ directory, you need a preceding RewriteCond. It's too late to append an extra rule when the first one has already executed.
RewriteCond %{REQUEST_URI} !^/chat/
RewriteRule {business about css here}