You must have /boot in Ext3 because a boot loader, which is just a simple program not equipped with a LVM driver, cannot read a LVM partition. All the rest can be inside a LVM. The /boot is for the boot loader to boot the kernel stored inside it. After the kernel has been booted it can read the LVM because it has the necessary driver.
You obviously have instructed the installer incorrectly, possibly with the first instruction using the whole disk impossible to execute causing the installer to make decision to have different partitions on your behalf..
Last edited by saikee; 06-09-2009 at 07:13 AM.