Loyal Jew, mixed buses are mutar. Rav Moshe held that cholov stam is muttar.
Rabbiofberlin, look in Yad Moshe to find where it is. Btw, by meals, if the women are not dancing, it is only a ma’alah — not a chiyuv. An important ma’alah, though, considering how mekushtos so many women are.