Upfront doesn't work very well with domain mapping

Today I found out that when you use original multisite domain for your admin area that Upfront doesn't load on a mapped domain frontpage.

Mapped domain admin to mapped domain frontpage is working fine
Original domain admin to original domain frontpage is working fine
Original domain admin to mapped domain frontpage doesn't work

I prefer to use my original domain for my admin because it's using SSL. The only solution/workaround I can think of is to switch temporarily to mapped domain admin when I have to use Upfront. Is there a final solution?

Thanks,

Splush
The Netherlands