As noonnope said above you may need to re-think this a little as it won't really be usable the way it is.
Fixed positioning is ok in small doses for things like a small header or footer but isn't really suitable for anything that will go below the fold such as your side nav.
Then your main text can run wider alongside your big image which could be fixed to the body as mentioned above. Set a margin-left on the content to keep it clear of the image.
I'm not sure what those image rollovers are for but they don't do a lot for me. They would be better off on their own page.
Too much absolute positioning makes for a layout that is too rigid and unusable and you need to let pages flow a bit better.
I did actually try to revive your page but it wouldn't come round