The problems that fedora causes are simply HDD geometry problems due to the way the 2.6 kernel series reads the partition table (I think).
I had this problem with FC2, I'm now on FC3 but I haven't checked the geometry yet, although a dual boot with FC3 and WinXP using Grub is working fine.
I only noticed the problem when I used Partition Magic 8 under WinXP to repartition my XP so I had a small FAT32 part that I could write too, as I don't fancy the idea of writing to NTFS quite yet.
I solved the problem as follows:
Boot into a live CD such as Knoppix, unmount and remount the affected HDD (will be hda in single HDD systems) and then I did the following as root on Knoppix:
root@knoppix]# sfdisk -d /dev/hda | sfdisk --no-reread --force -H255 /dev/hda
Please be aware that this may not be the same for you if your HDD geometry is different - I suggest finding out the info of your HDD geometry first using a liveCD first before trying this.