yum + mulitarch + updates

[dragoran <dragoran feuerpokemon de>]

I have noticed that when I have package foo-1.0.i386 installed and some 
other (x86_64) repo has foo-1.1.x86_64 yum updates foo and removes the 
i386 one.
(livna mplayerplug-in was it here).
Updates should not be crossarch a i386 package should only be updated to 
a i386 one (same for x86_64).
Any reason for doing this? Or is this a bug thats needs to be filled?