A: 

probably u should try with

RewriteRule (.*) http://domain.com/$1 [R=301,L]

Sabeen Malik
On the first Rewrite rule? Trying now.
Rory Hart
Nope doesn't work. Thanks for the suggestion!
Rory Hart
so if i understand the problem correctly.. when IE goes to http://www.domain.com/?p=520 .. it just stays on that url ? and if any other browser goes to that page then they are redirected to http://domain.com/?p=520 ?
Sabeen Malik
A: 

I will answer why "www.domain.com" was "domain.com", the 3rd party developer must have been under the deprecated www movement.

Basically, it shouldn't have affected any of the browsers. I do suggest resetting your cache and or flushing your dns.

Try removing:

# Rewrite rule for wierd redirect issue
RewriteCond %{HTTP_HOST} ^www.domain.com$
RewriteRule ^/?(.*)$ "http\:\/\/doman\.com\/$1" [R=301,L]

Reupload then see if it works properly. If not, delete your cache. Refresh to see if it works properbly. And if it still not, try flushing your DNS.

If you using Windows, you can flush your DNS from the Command Prompt.

These are the steps I take:

  1. Start
  2. Run
  3. Cmd
  4. ipconfig /flush-dns

For any other O.S. I am unsure how to flush the DNS.

I usually take these precautions when I switch hosts for the domain name but this may be related as it is domain related. Hope that helps.

I also want to add that a regular Wordpress .htaccess file looks like this:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

So if all else fail, just replace everything with the basic Wordpress .htaccess code.

Good Luck :)

Anraiki
Thnx for the excellent answer. None of this helped I'm afraid I've come to the conclusion it is something wrong with the host and have put in a support ticket. Fingers crossed they sort it out, I've advised the friend to move hosts in any case as this isn't something I've seen before. Thanks Again!
Rory Hart