Permalink htaccess help?

I'm trying to create permalinks like this : /%postname%/.

I created an htaccess file as described here: http://codex.wordpress.org/Using_Per...access_file.3F

Anytime I change the permalinks to anything other than default, the pages disappear. Creating and updating the htaccess file did nothing other than get rid of the error message (that I need to create the htaccess file). Anytime I edit the htaccess file, all of my edits get deleted.

The file permissions aren't the problem. Set at 777 until I can figure this out.

I'm working with a client who's host is relatively... un-equipped. So that may be the issue? Or more likely my own ignorance.

Any ideas?