We have tried a few other partition managers and here is a summary:
Vector Linux 5.8 cfdisk (from installer): failed
Vector Linux 5.8 fdisk (from CLI, busybox): failed
Damn Small Linux 4.2.5 fdisk (busybox): failed
Ubuntu 8.04 Live CD gparted: passed
Knoppix 5.1.1 Live CD qtparted: passed
I do not know if that will help find a better cfdisk/fdisk version for Vector, but this seems to be an issue with the BIOS not seeing what it expected while detecting harddisks. The BIOS in the E4100 locks up before it even starts the process to find a bootable device, so it is not possible to boot from CD with the affected harddrive connected to the motherboard. It locks up before you can enter the BIOS menu.
In any case, the work around currently is to boot from Knoppix 5.1.1 Live CD and run qtparted to clear the partition table and create the partitions for install. Then, run Vector Linux install and skip the FDISK step. The install process performs normally after this point.
For the affected harddrive to be usable again after being partitioned by the installer and locking up the BIOS, you must connect the harddrive to another computer or connect it to a USB-to-IDE bridge (such as an external harddrive case) and zero the first sector. A simple `dd if=/dev/zero of=/dev/hda bs=512 count=1` seems to work, but you loose all partition and MBR information. This step should not be necessary if you are clearing the partition table using qtparted, but has not been tested.
SQI will be writing a troubleshooting article for this issue on the Knowledge Center at http://vector.ecosq.com/