Hi
Ubuntu 'natty' switched to multiarch recently and my cross toolchain packages started to fail to build. Most of problems were fixed but then dpkg-cross hit us.
Today I looked at dpkg-cross and made attached patch to handle problem. What patch does is converting multiarch packages into old style ones. There is no extra switch like "--force-even-when-multiarch" and "--convert-anyway -A" is used instead. This is change against latest CVS code (dpkg-cross r1.83).
From my tests it looks like it does proper job.