Doesn't work and can't login to admin

I successfully installed the component, but there's no effect. When I add the .htaccess file, every link on the site turns into

Warning: [obfuscated]() [function.[obfuscated]]: REG_BADRPT in /home/playbeta/public_html/components/com_sef/sef_func.php on line 0

I can no longer log into the administrator panel as well.  When I remove the htaccess file, the site looks fin and I can log in to the admin, but no URL rewrites. I thought the install was supposed to be "easy"?

Please contact me on mail regarding this specific issue. It is some error specific to your site.

You had "+" sign as space character in configuration. This misconfiguration resulted in errors.
You should use hyphen "-" or underscore "_" as word separator.

When you get errors always revert back to default settings to see if the error depends on your own configurations.

Thanks for the tip!  I was using shf404 before and was able to use the plus sign as a word separator in the URL. Is this not advisable for make the most Google-friendly URLs?

It turns out that this was not my server problem but a problem with the htaccess file included with SEF Advance.

Also this extension DOES NOT WORK if you've modified your core Joomla installation.