I've tested your analysis and confirmed that was NOT the
misspelled "CLASSS." Correcting the misspelling must have been 
coincident with something else. I wish had taken better notes.

I'll continue to test to see what clobbered class list entry.
-ben

Carsten Dominik wrote:
> Hi Ben,
> 
> I don't think
> 
>  #+LaTeX_CLASSS_OPTIONS: [presentation]
> 
> can mess with org-export-latex-classes.  You must hve been missing 
> something else.
> Try to re-introduce the line - I am sure it will work just fine.
> 
> - Carsten
-- 
Capt. Ben Smith
R/V Coastal Surveyor - R/V Cocheco - S/V Mother of Perl
Center for Coastal and Ocean Mapping Joint Hydrographic Center
University of New Hampshire, Durham, NH, U.S.A.