When root=805 (i.e. hex number notation) is used in the kernel command line, the init script from genkernel initramfs fails to find the device, however root=/dev/sda5 will work.
I use sys-kernel/genkernel-3.4.45 with a user-defined kernel config and manual lilo-configuration.
Steps to Reproduce:
1. Use initramfs from genkernel.
2. Use hexadecimal device number in the root= option.
3. Boot the system.
init will not find the root device and fall back to a promt
init finds the root device and mounts it
Use a more modern config; device numbers are liable to be dynamically generated now.