What is the exact url on each try? (Including http:// or https://)

The error usually happens when you set your URL as www.xyz.com and you access it without the "www" prefix or vice versa.

Your site is installed without the "www" prefix and you are trying to access it with the www prefix.

Try this fix http://docs.elgg.org/wiki/Login_token_mismatch_error 

This how we have our present "rewrite/redirect" string

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

And for those of you curious to see how this "tiny" error acts, here is the url and a testing account.

url: www.crossovermagazine.com

Username: Elggrules

Password: support

As I said. When you see the error, simply login again, and all is fine. That's the only glitch. Beyond that, I can ONLY sing praises for Elgg and the community as a whole.

Maybe I'm wrong, but I cannot see a redirection happening in your site, I visited www.crossovermagazine.com and I stayed there, I visited crossovermagazine.com and I stayed at the website without 'www'.
This way, that error will stay because no redirect is happening

Are you sure you have "RewriteEngine On" before your other rewrite rules? You need that precursor.

Anyway, just to be sure, in case you added the RewriteEngine On on you htaccess and that's not the problem.
I'm gonna give you my htaccess rules from which I am 100% sure they work in a normal 'Apache' environment.

add this on top of your htaccess file :

RewriteEngine On
RewriteBase /
RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]

@Crossover Magazine Add these rules in your Apache config (usually, in httpd.conf)

NameVirtualHost 0.0.0.0


ServerAdmin webmaster@localhost
DocumentRoot /var/www/crossovermagazine/www
ServerName www.crossovermagazine.com
ServerAlias crossovermagazine.com *.crossovermagazine.com
ErrorLog /var/log/apache2/crossovermagazine_error.log
CustomLog /var/log/apache2/crossovermagazine_access.log combined

<Directory /var/www/crossovermagazine/www/>
Options FollowSymLinks
AllowOverride All
</Directory>

instead of using .htaccess for it

To Dries: You may have hit the nail on the head with you last reply. Will keep you posted if anything else pops up in the future.

Thanks again for being there bro.