403/404 pages

First, thanks for a great theme!

My question is the following:
I created two page nodes - one for 'access denied', the other for 'not found'.
Now when I try to access the content I don't have permission to the 'access denied' page nicely pops up and everything is fine. However, when I try to go to 'not found' page (by typing a wrong link) I do get my page but none of the blocks are displayed. I.e. as if the right and the left sidebar had no blocks at all (even though those blocks appear when i go to 'access denied' page).

I believe both the 404 and 403 node pages should display all blocks...

Do you have an idea why this is so?

thanks