File access

Hi,

I'm trying to use Slideshow Creator to display files I have in sites/default/files/pictures.

I have successfully used SC to display images that are publicly available on the internet however I can't seem to display my own images.

I'm using the following markup:

[slideshow: 2, rotate=2, blend=1 height=400, width=400, dir=|sites/default/files/pictures|yes||Generic Photos|Aren't they great?||]

As far as I can tell this is correct.
The permissions of the all the files and the images are set to 755.
I have clean URLs enabled.
I have the input formats correctly configured (as they work for external images).

I suspect it isn't an issue with SC but with file access in general.
I have set my File sytem path to sites/default/files.
The download method is public.
However I can't directly access the files over the internet.
Do you think this is the problem and if so how could I fix it?
Or am I doing something else wrong?

Thank you for any help.