Are you running windows XP? It looks like hdb doesn't have the lilo installed on it, or it is loading from something else instead. Can you change the boot drive to the hdb drive in bios. If so, you could make hdb your lilo boot drive, and follow the instructions from one of the NT Linux Dual-Boot howtos. I had a similar thing happen when I tried to install linux to a promise raid drive. The kernel versions didn't match perfectly, and I was able to install linux but not boot up. After updating to an even more recent kernel I ended up installing Linux on a non-raid drive, and kept Windows XP on the RAID drive. I set up the boot drive to my linux drive in BIOS, and followed the instructions from the how-to. Now I boot using the raid drive and select linux from the NT Loader screen with the original raid drive.
I hope this helps.
My main point, is that I temporarily used bios to select the boot drive until I had things set up properly.