File permission error on Manager page

I installed Revo today to kick the tyres and successfully connected to the database and had ’success’ messages on all further install steps. When I chose to delete my setup folder and go to the Manager for the first time, I get an error message

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

I have followd all the steps mentioned here

# Make sure the directories "/[root]", "/core/packages","/core/cache", and "/core/export" are writable. (root will be the actual directory you are installing to.)
# Make sure "/manager", "/connectors" are writable. If installing advanced, this is unnecessary.
# Make sure your php.ini setting sets memory_limit to 128M, and max_execution_time to 120
# Create a blank file "/core/config/config.inc.php" and make it writable. DO NOT COPY config.inc.tpl! Just make it a blank file!

Any ideas?

This isn’t coming from MODx as such, its a general perms error, see here for an example http://www.bleepingcomputer.com/forums/topic239627.html there are others if you google.

Thanks shamblett

I’m familiar with the type of message but had assumed it was a ModX related issue.
I’ll check that the FTP app actually uploaded everything.