Spell check is lost when using ContentType = "application/word"

[Guest]

For some reason when I direct my users to a word document via
Response.ContentType = "application/word" the spell check is turned off.
Does anyone know which smart tag needs to be mofied to have it on by default.
It appears as though it might be <w:SpellingState>Clean</w:SpellingState>.
However, I haven't found any web sites that discusses what alternative values
of this tag might will accept. Any help would be greatly appreciated.