Hi Ralf,
I'd recommend you to file a bug against rpm and leave it to the rpm-maintainer to respond.
Well, I guess that would take its time ... but I would like to have a useable system now ;)
However, I'd guess the issue you are facing actually is an issue with some fs-relates syscall underneath misbehaving.
Actually its not misbehaving, its just about different expectations - and RPM even provides an option (--ignoresize) to turn off those checks. However, I haven't found a way to make yum pass that option to rpm, so for now I am forced to install RPMs manually instead of using yum :(
Thanks, Clemens