I noticed this on 12.10 trying to get the Android SDK working. For 64 bit versions, it is required to install:
sudo apt-get install ia32-libs
However, under 64bit 12.10, I got the following error:
The following packages have unmet dependencies:
ia32-libs : Depends: ia32-libs-multiarch but it is not installable
And
> apt-get install ia32-libs-multiarch
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package ia32-libs-multiarch is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'ia32-libs-multiarch' has no installation candidate