No space for new partition on SATA drive, but 61GBfreespace

[Nigel Henry]

This is the first time that I've used SATA harddrives on this new machine that 
I've built, so am a bit in the dark.

Fedora 8 is using sda1 for / , and sda2 for /home. sda3 is swap

sda4 (the 4th primary is the extended partition)

sda5, and 6, are / , and /home for another linux distro
sda7, and 8, are / , and /home for another linux distro
sda9, and 10, are / , and /home for yet another linux distro
sda11, and 12, are / , and /home for another linux distro

There is still showing 61020 MB of free space on the drive, but trying to 
create a new partition for the install of Fedora 9, with 10000MB for / I get 
the following output. Written in freehand.

Error Partitioning

ould not allocate requested partitions: Partitioning failed: Could not 
allocate partitions as primary partitions. Not enough space left to create 
partition for /.

I'm sure I've seen some stuff about partition limits on SATA drives, but can't 
remember where. If there are limits, are there any workarounds so that I can 
use this 61+GB of freespace.

Thanks for any suggestions.

Nigel.