Id SDK_ARCH INST_ARCH Status
==============================================
1 ix86 ix86 works
2 ix86 x86_64 works
3 x86_64 ix86 cannot work
4 x86_64 x86_64 works

The bug report is about case 3 - attempting to install a 64 bit SDK on
a 32 bit machine. This indeed cannot work and shuld be prevented byy
the installer.

But the current code also prevents case 2, installing 32 bit images on
a 64 bit machine, which works perfectly fine (assuming you have the
needed 32 bit libraries installed).