Help - Newbiee

Hi all,
I know how annoying us newbies can be but I've struck a complete dead end.

This isn't the first time I've used FTP, it is however the first time I've set up an FTP from scratch. (I used someone elses settings before rather than make my own)

Now I'm using Dreamweaver CS5 and I'm ready to publish - but this is where things go wrong !

My FTP settings are correct because the test connection works (& I've got passive mode ticked).
Now when I go up upload, I get this error message ...

"Started: 15/01/2011 13:28

index.htm - error occurred - An FTP error occurred - cannot put index.htm. Access denied. The file may not exist, or there could be a permission problem. Make sure you have proper authorization on the server and the server is properly configured.

File activity incomplete. 1 file(s) or folder(s) were not completed.

Files with errors: 1

Finished: 15/01/2011 13:28"

I've searched through my web host & made sure everything is correct & that I have the right authority.
I just don't know what else to do or try.
It's driving me mental, so any help at all would be amazing and fully appreciated.

Thank you in advance!