joyride build - versus - yum update

[Mikus Grinbergs]

> Changes in build 1544 from build: 1543
> -olpc-library-common 1-18
> +olpc-library-common 1-19
> -olpc-library-core 1-19
> +olpc-library-core 1-20

Because I apply customizations, it takes me considerable time to do 
an install of a new build.  Instead, I prefer to run 'yum update' -- 
that lets me keep my existing customized os, and simply put in the 
newest modules.

But NOT all new modules that show up in new builds are being found 
by 'yum update'.  For example, 'rpm -q ___' shows the two modules 
quoted above to still be at their previous levels on my system.

How come the new levels of these two modules were put into a build, 
but not into the repository which 'yum update' looks at ?

mikus