Nusach S'farad, in the amida ("sh'mone esre") of holidays and Shabas, has "וְשַׂמַּח נַפְשֵׁינוּ בִּישׁוּעָתֶךָ" ("v'samach..."), but in sheva b'rachos it has "שַׂמֵּחַ תְּשַׂמַּח" ("sameach...").
Nusach Haari does the opposite: in the amida it has "וְשַׂמֵּחַ נַפְשֵׁינוּ בִּישׁוּעָתֶךָ" ("v'sameach..."), but in sheva b'rachos it has "שַׂמַּח תְּשַׂמַּח" ("samach...").
Why?