403 Forbidden

[#1]

I’ve set up a very simple site http://www.whitenine.plus.com/ but clicking on portfolio opens a new window saying I don’t have permissions to access /portfolio.html on this server. Why not? I created a virtually identical portfolio for my employers and that worked first time, so I don’t see why this isn’t working. Please help.
Thanks

[#2]

Sorry, first question has to be have you checked that portfolio.html file permissions are set to allow the browser to read the file?

[#3]

I've never had to check permissions before, my uploads have always just worked. Anyway, I discovered that the portfolio file and a lot of other associated files had no access for visitors. However, each time I tried to change the permissions, they just changed randomly, sometimes even I had had no access to the files! I've deleted everything until I can figure out a way around this. I've never had any problems uploading a site before. Very frustrating.

[#4]

Must have been something to do with my ftp client. No idea what caused it, but I tried a different ftp client and it all works now.
Thanks for the advice.