I'm not sure if I can help with everything, but if a distro doesn't recognize your LDM volumes, then it probably doesn't have it at all. It's either build into the kernel of the distro, or not.
If you installed Vista at any time, then you'll need not just a distro with a kernel with built-in LDM support, but also a kernel that's newer than 2.6.21 or 2.6.22, not sure which.
But why use dynamic disks (LDM) in the first place? I guess you use it for Software RAID? I'm assuming that you have RAID 0 (i.e. I'm assuming the second scsi should also have dynamic partitions that are in RAID 0 config with the first)?
In that case, you'll need to do as mentioned. Else, isn't it easier to backup, convert to basic discs, then install the distro of your choice?
If you insist on LDM, (for RAID 0 speedy loading) there is a workaround. create a basic partition on your IDE disk. Install Ubuntu or any distro of your choice there. After the install, you'll need to update your kernel to the laaaatest version, and make sure to chose the option under filesystems that enables linux to recognize and work with LDM. install the kernel. then reboot. You should now be able to see all your partitions on the dynamic disk. Then just copy (don't move, I'll explain later) your whole linux installation there.
GRUB probably can't recognize dynamic disks, and won't be able to boot off of them. A solution is to keep your original linux install on the basic partition on the IDE disk, which is why I said copy don't move earlier. You don't need everything,just the /boot folder, so that GRUB can load the kernel off the basic partition. You can delete the rest once you're done. The only thing you have to do now is make the kernel GRUB loads off the basic IDE partition choose your linux ldm partition as its root. You do this by modifying the "menu.lst" file in the /boot/grub directory on the basic partition, assuming you use GRUB as a bootloader.
In the "menu.lst" file, you'll find a place where it says kernel="KERNEL VERSION" where "KERNEL VERSION" is a number, the version of your kernel. On the same line, you'll find root="something", where something is your old basic partition. replace it with the linux ldm partition.
One last important note. If what ever partition on the LDM disks you want to access, if it's Software RAIDed, you also need to install mdraid, after updating your kernel, or else you're kernel won't be able to access those partitions. if you do access them without mdraid, you can corrupt them. You'll need to configure mdraid, and pass another kernel option at boot time to recognize the partitions.
Hope this helps