Where is my 2G? - BUG in Ubuntu?

[Brian Astill]

That 2G I "lost" is still lost :-(
Worse, when I login Dapper insists I have no home directory!

/etc/fstab says:
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    defaults        0       0
/dev/hda2       /               ext3    defaults,errors=remount-ro 0       1
/dev/hdb7       /home           ext3    defaults        0       1
/dev/hda5       none            swap    sw              0       0
/dev/hdc        /media/cdrom0   udf,iso9660 ro,user,noauto  0       0
/dev/hdd        /media/cdrom1   udf,iso9660 ro,user,noauto  0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto  0       0

So, what the fsck?  What have I done wrong, or what have I forgotten?

As a temporary fix I copied the dot files from hdb7 to hda2/home.  
Not only does this "work", but Ubuntu then recognises home on hda7!
But, as you can see below, the overall effect is that I have moved 3.9G
 of files away from hda2 for a net gain of 200M!  :-)

root at hoarykde:/ # df
Filesystem           1K-blocks Used Available Use% Mounted on
/dev/hda2             11661852   9028288   2041168  82% /
varrun                  387788       144    387644   1% /var/run
varlock                 387788         4    387784   1% /var/lock
udev                    387788       152    387636   1% /dev
devshm                  387788         0    387788   0% /dev/shm
lrm                     387788     18856    368932   5% /lib/modules/2.6.15-28-386/volatile
/dev/hdb7             11258648   3903072   6783664  37% /home  

I found kcore - 804.8M - in /proc with all the zero-length files 
and directories.  Could this be part of the problem? 

How can I restore my system to health and have the 5G free
 on hda2 I should have?

Thanks.
  
-- 
Regards,
Brian