Hi,
I have the same problem.
It seems related to the blog theme.
As you did, I also copied Aero to the default folders to enable it as my default themes, including in the blog section.
The problem is that the Aero "blog theme" must somehow refer to the Aero main theme to display.
The issue comes from the fact that a user can modify his main theme, but not the blog theme he is using. Thus, when selecting a non Aero theme, CS is still looking for Aero parts when viewing blogs which are still set to be displayed with Aero.
Do you have an idea to fix that easily, or shall we wait for Aero 2007.
I have many users who would like to have the ability to chose a lighter theme, especially when browsing under Linux, since Aero makes browsers consume a lot of memory resources.
Thanks for your great theme and your help Nick 
Edit: The weird thing is that the blog view only crashes if you use basic_blue or alternate1 themes. It works if you use the CS default theme. It must have something to do with the "blue" based themes.