The current text (for SO) on the right of the new question page states:
How to Ask
Is your question about programming?
We prefer questions that can be answered, not just discussed.
Provide details. Write clearly and simply.
If your question is about this website, ask it on meta instead.
Fact is, we have several "programming" questions being asked on Meta, and recently about websites.
Could it be that "this website" is potentially confusing for someone who wouldn't be at ease with English? Maybe they think that website questions should go there. (I don't think it's a majority of what happens in misplaced questions, but let's focus on this case).
Maybe this last sentence could be changed to something like:
If your question is about stackoverflow.com itself, ask it on meta instead.
There would probably be less of a risk of misunderstanding, in this particular case.
Edit: Example of misguided user (thanks to Grace Note):
oh sorry. i tried to post the question in stackoverflow and the dialog told me to post it here ... so where shell i post it??