Been running Lucid for a while, now, but still have a lot to learn.

This computer has three hard drives: two 40 GB IDE drives and one 500 GB
external drive (USB connection). The first 40 GB drive has Win XP, and the
second has Ubuntu (It dual-boots, using GRUB2). The external drive is used for
backups.

Question 1: Disk Utility 2.30.1 correctly reports the partitioning and
capacities of the three drives. However, it does not report how much of each
partition is used or available. Is it supposed to?

Question 2: With nothing of the WinXP hard drive mounted, and the external 500
GB drive mounted, Disk Usage Analyzer, Baobab 2.30.0, reports the total
filesystem capacity as 500.9 GB. Is it not seeing the 40 GB Ubuntu drive? / has
a 15 GB partition, and /home has a 23 GB partition.