Ross's Paradox, "ought", and "wants"

Ross's Paradox is a problem arising in Standard Deontic Logic. On the SDL interpretation of "ought", obligations survive weakening, in the sense that, if P entails Q, and it ought to be that P, then it follows that it ought to be that Q. Ross's paradox involves an instance of this commitment.

1) Jones ought to mail the letter.
2) Jones ought to mail the letter or burn the letter.

According to SDL, (1) entails (2), but, intuitively, (2) seems false in situations where (1) is true. Intuitively, (2) suggests that it is permissible to either mail the letter or to burn it, while (1) would seem to rule out the permissibility of burning the letter (it being assumed that you cannot both mail it and burn it).

I recently noticed a parallel between (2) and the following sentence:*

3) Jones wants a dog or a cat.