Recently helped some friends install Redhat 5.2, and when setting up their partitions with fdisk, we incorrectly selected hit "a" to add a partition (this is instead the cmd to toggle the bottable flag). Pressing <ENTER> alone did not abort the prompt so we hit Ctrl-C to abort the command. Amazingly, the kernel paniced and the system rebooted.
I have verified that this does occur as the user has reported. Hitting control-c does in fact hang the install.
Fixed in next release