10.10 came out, same bug.  I implore you to open this bug for upgrade.  "no activity" is result of complete disabling of MY computer for one, and I suspect upgrade information needed on HDD formatting.  Please excuse the reference here (and not in Maverick Meerkat version bugs) but I think this needs to be tied into what will ultimately be MicroSoft around the boot sector.  After bashing around I finally started locating directories and some terminal commands.
Observations:  please note "the treatment"
   Live CD: 10.04 and 10.10 (same result)
      boots to a login screen
      login/password combinations return to login screen
      IE; does not work at all
      : no other behaviour

   Install Ubuntu 10.04 and 10.10 (same result)
      (before "the treatment")
      installs to restart and hangs on "Enter"
      hard power off to restart
      boots to a login screen
      login/password combinations return to login screen
      login/select safemode desktop/password starts as expected [in Safe Mode]
      seems to run as normal load for normal activity  WHY SAFE MODE only?
      /dev/sda1, /dev/sda3, dev/sda4, dev/sda5, dev/sda6, dev/sda7, exist: but only 3 partitions were created during install AND AND AND AND the three partitions created "used the entire disk".  How did I do that?  I DON"T KNOW! and what happened to /dev/sda0 and ...2?
      : no other behaviour

      (after "the treatment")
      10.10 installs exactly as expected
      /dev/sda0 partitioned with 20Gb root sda1 & 470Gb home on sda5(???) & what was left as swap on sda7
      boots all the way to login screen
      login/password combination blinks, loads desktop, returns to login screen
      - info note? - in the 0.67 seconds it starts to show the partial desktop, it appears to be able to respond to GUI inputs before it dumps back to the login screen
      login/select safemode desktop/password starts as expected [in Safe Mode]
      seems to run as normal load for normal activity  WHY SAFE MODE only?
      terminal command df - shows /dev/sda1 root, /dev/sda5 home (swap does not show I guess)
      Question - is it significant that /dev/sda1 and 5 seems to be written onto the disk as though there are partitions 2,3, and 4 still containing previous loads?

"the treatment"
failed load of 10.04 incensed owner to delete all information using Gparted from 9.10 Live CD
repartition did not change login loop - multi-boot grub was noted to contain WinXP, two previous versions of ubuntu AND 10.04.
shred command was used on 500Gb drive - lots of time wasted - no improvement. multi-boot grub still present
10.10 issued and loaded and login loop noted
owner deleted all information using 10.10 Install partition application and reloaded several times using incremental changes.  exact same login loop.  local support claims hardware issue.  noted multi-boot grub still present.
used IDE to USB interface and used Apple backup computer's DiskUtiflity to format to journaling type?OOPS?
attempted to use 10.10 live CD
login screen loop
attempted to install 10.10 - upon reboot mutli-boot grub is gone
login loop again
boot to safe mode
not knowing anything about grub, tried to remove it using "fdisk" from Win98 rescue disc
deleted all files/partitions according to limited MSDos fdisk
"grub recovery mode>" showed up.  I couldn't do anything with it.
install 10.10
login loop.

PLAN to use Apple backup system to reformat HDD to FAT32, use a shred command, reload 10.10 using ext4
INTENT is to get whatever old references to long gone boot options to disappear.

it is my sincere hope that someone may find this information useful to prevent others experiencing this drifting and floundering conundrum.