Insane Problems with Installing on Heart Internet

Well as it says above in using Hosting on Heart Internet,
I've tried this over 10 times now. I've followed the Installation Guide through down to every word. But everytime i go to the directory where it's at, i get the same annoying message:

A file permissions error has occurred. Please check the permissions on the script and the directory it is in and try again.

I've checked, double checked and triple checked all permission settings on the relavent files according to the guide and still no luck. I've also added the line shown below to make sure php5 is used...But still NOTHING

SetEnv DEFAULT_PHP_VERSION 5

I need help with this, nothing seems to work....

Thanks in advance

Some hosting providers (eg. Hostmonster) require permissions on certain files (specifically index.php, admin/index.php and install/index.php) to be set to 0664. That is, readable/writable by the owner and the group, but read-only for everyone else.

Hope this helps.

Ah ok, yea i gave it a go, it seemed to work after i set install/index.php to 0755 even thought the guide said nothing about it. Thanks