.htaccess and Admin Area Problem

[Sanguinarius]

I'm using ZC 1.5.0. new install from my hosting company cPanel. I have SSL and all that.

I wanted to make the following urls all automatically forward to https://www.sanguinarius.org/store/ :

http://www.sanguinarius.org/store/
http://sanguinarius.org/store/
https:/sanguinarius.org/store/

I contacted my hosting company and they told me to use a .htaccess file with this in it:

RewriteEngine On
    RewriteCond %{SERVER_PORT} 80
    RewriteRule ^(.*)$ https://www.sanguinarius.org/store/$1 [R=301,L]

and upload it to my store directory. (That is so the rest of my website doesn't get forwarded to https://;blahblahblah.

OK, fine. I did that. Then I went to edit a product and submit it to the database and I get the pink strip at the top that says:

Error ERROR: The data you submitted was found to be empty. YOUR CHANGES HAVE *NOT* BEEN SAVED. You may have a problem with your browser or your internet connection.

=====

What did I do wrong and how do I make it right short of removing the .htaccess file and having people going to http://www.sanguinarius.org/store/ and it not being secure? Or do I remove the file and do something else that you ZC guys here know about but my webhost's tech support doesn't?