System: Dell Inspiron 3700 I installed RH 6.2, and then all the official updates for it. I also compiled a new kernel (2.2.16) and the pcmcia pack (3.1.19), plus installed a lilo from rawhide that has lba32 support. Then I tried to rebuild som src.rpm packs. It failed in the end when the binary rpm-pack was to be created. The problem seems to be with the rpm updates (that is rpm itself) for 6.2. When I made a fallback to the original 6.2 rpm I could rebuild the packs again without any problems.
rpm-3.0.5 has the same default configuration for building that rpm-4.0 does. Either 1) fix the (now legacy) package that you are building (recommended) 2) use rpm-3.0.4 or earlier to build (easy) 3) use rpm-3.0.4 macros with rpm-3.0.5) (will work, of questionable utility).