what partitioning rule am I not aware of?

[Tom Horsley <tomhorsley adelphia net>]

In an excess of energy I decided to see how many different OSes I
could install to compare their behavior with a weird X bug I
encountered in FC6:

https://bugs.freedesktop.org/show_bug.cgi?id=8790

I figured 20 gig was about enough for each root, and decided to
create 7 small /boot partitions near the front of the disk (since
so many boot loaders have problems with big addresses) and 7 20
gig partitions after that for different kernels (my disk is a 160
gig sata drive).

Windows has no problems doing this, but fdisk -l won't print any
info about partitions after /dev/sda15 and if I try to install
FC5 on a system that actually has an sda16 and sda17 partition
(even if I don't try to use them for anything), anaconda blows up
at the partitioning stage when it is about to try to partition
and install.

If I go back to windows, delete the last two partitions, and
re-install, all goes smoothly.

Is there some rule I don't know about on the number of
partitions? Or is it a rule about the starting address of a
partition (can't be too big maybe)?

Its really very irritating that they keep making disks bigger and
bigger and software never seems to know what to do with them :-).