ModRewrite weird redirect behavior on removing WWW

I'm trying to use some rule on my project to remove www from the beginning of the URL but I've some problem.

my server structure is:

domain.com/beta_folder
domain.com/beta_folder/page+type
domain.com/beta_folder/page+type/content+name
domain.com/beta_folder/page+type/content+name/edit
domain.com/beta_folder/page+type/content+name/etc.

domain.com/beta_folder/.htaccess //here is where my htaccess is

beta_folder is the site folder, and content+name are content vars, created to retrieve pages from the database.

the site works perfect with this rules

RewriteEngine On
RewriteRule ^(page\+type/)([a-zA-Z0-9_+-]+)[/]?$ page_folder/page.php?varname=$2

My intention was to remove www, so I've added this rule but it isn't effective

RewriteEngine On
RewriteCond %{HTTP_HOST} ^www.domain.com$ [N开发者_StackOverflow中文版C]
RewriteRule ^(.*)$ http://domain.com$1 [R=301,L]
RewriteRule ^(page\+type/)([a-zA-Z0-9_+-]+)[/]?$ page_folder/page.php?varname=$2

My problem starts if I digit www in front of my domain name:

this works

http://domain.com/beta_folder/page+type/content+name

if i write

http://www.domain.com/beta_folder/page+type/content+name

the rewrite rule redirect me at

http://www.domain.compage+type/content+name

if i remove the www rules, the problem still active

unfortunately, I can't make a public test for my domain

basically, if I write

 http://www.domain.com/beta_folder

the rules sends me to

 http://domain.com/

the only way I've found to solve the problem is to write the folder where my site is, so:

RewriteCond %{HTTP_HOST} ^www.domain.com$ [NC]
RewriteRule ^(.*)$ http://domain.com/beta_folder/$1 [R=301,L]

I don't undestand why I should write the folder, because my rewrite cond affects http://www.domain.com/folder_name/contents and not http://www.domain.com/contents

why folder_name missing from the rewriting?

Try this, subtly different example of your rule:

RewriteCond %{HTTP_HOST} !^www.domain\.com$
RewriteRule (.*) http://domain.com/$1 [R=301,L]

Shout out if this doesn't solve your problem.