Unable to boot new FC3 2.6.10 kernel. Have done all my research

Good morning, all.

OK, I give up.

No matter what I do, building a new kernel for Fedora Core 3, kernel version 2.6.10, and then booting from the new kernel, gives me the following boot time error:

Unable to find device-mapper major-mnor Reading all physical volumes. This may take a while... Found volume group "VolGroup00" using metadata type lvm2 dev-mapper-control: open failed: No such file or directory Is device-mapper driver missing from kernel?

It then goes on to give me a kernel panic.

Booting from a distribution kernel (e.g. the one that came with the FC3 distribution, or the one received from Update) also talks about "reading physical volumes" and "found volume group..." and then goes on to boot successfully.

I know you all hate it when people come on here asking all kinds of newbie-type questions without doing their research first, so I will report that I have done the following:

** Read through everything I can find that has anything to do with kernels;

** Read the (somewhat-outdated) README that comes with the kernel sources;

** Google'd every word and phrase I can think of that might point to this, and read through the resulting articles ... most of them have to do with upgrading from 2.4.x to 2.6.x and from lvm1 to lvm2, neither of which relates to what I'm trying to do here (note that the out-of-the-box kernel, which is already 2.6.10 and uses lvm2, works fine).

** Read through every single kernel configuration option to see if I could find something that might apply, that's not getting enabled.

I have been building custom Linux kernels since about 1995 or so, so it's not like I'm exactly clueless about this kind of sfuff.

Clearly there is some kernel configuration option that's not getting set, but short of just going through and enabling everything (not generally a good idea), I don't know where to go next.

Suggestions appreciated...

CJ