How to apply coupon in domain+hosting combos?

[Kaushik]

Hi,

i have created a new order form named combo and i have chosen following:

1. Type: Domain & Others.
2. Allow Coupons: Yes.
3. Package Group: Hosting (Ive created coupons for these).

When i choose domain and hosting package using this combo page, coupons are not getting applied where as if i choose only the hosting, coupons are getting applied.

Where did i miss? Can anyone guide me where i have gone wrong?