It happens from time to time - for example today: amd64 users are confused when they get an error message on installing the latest amd64 packages of XBMC-PVR-Testing from the hepi/yaVDR PPA via apt:

xbmc-data: Depends: xbmc-bin (< pvr-testing-32~hepi-lucid29507.1~) but pvr-testing-33~hepi-lucid29722 is to be installed

The reason for this is that Launchpad has finished building the amd64 packages before the i386 packages were built. How can that be a problem? Some of the packages that XBMC consists of, are marked as platform independent. This means, they only have to be built once and can be used on both platforms, be it i386 or amd64. Launchpad builds those packages marked as platform independent during the i386 build and ignores them during the amd64 build.