BT4 and Ubuntu can't live on the same multiboot USB drive

[Charrit]

I made a multi-boot USB pendrive with several live distributions, and I found a problem:

BT4 doesn't load properly, I supose that BT4 is mounting the squashfs from the Ubuntu distribution during the booting process. I think this because when BT4 finishes the boot process, it shows the motd for Ubuntu 9.10, also, during the booting process it hits some errors of missing libraries and it doesn't make the autologin...

Tech data:

sda MBR has Grub installed and chainloads other systems for preserving distro menus
sda2 has Ubuntu 9.10 Live with Syslinux installed in the partition
sda3 has Back Track 4 Final with Grub installed in the partition

I found a partial fix for the problem, if I rename the "casper" directory of the Ubuntu (sda2) to "casper_disabled", then I'm able to boot BT4 with no problem.

Any idea to avoid that problem?

Thanks!

[Archangel-Amael]

This is not a bug. Post in the correct section, there are labels to help you.

[Charrit]

Ok, I'm sorry.

But I'm still think that it is a bug:

Why BT should load a squashfs that it isn't located in the root partition?

The kernel and the initrd images are correctly loaded from the root partition of BT (sda3), I think that the problem is in the init scripts after the kernel is loaded. These scripts find the first partition that contains the "casper" directory, but why don't they use the root partition to do that?