Comment 2 for bug 22225

I've had a similar problem, as detailed below:

Install of Ubuntu 5.10 Preview freezes at 85% of "Installing Packages" stage. No
package named in the box. Message is "Preparing for installation...". I left the
machine for >20min (I don't know exactly how long, as I wasn't attending it when
it got into the stuck state). Switching to another console, top shows no process
using an unusual amount of CPU or memory, and ps doesn't reveal anything that
looks out of the ordinary (with the caveat that I'm not at all familiar with the
Ubuntu install process, so there may well be something that I couldn't spot). A
brief summary of my hardware (I can provide more details if needed):

AMD Duron 733
Shuttle SN45Gv3 case with FN45 mainboard
nVIDIA nforce2 chipset including onboard ethernet (connected to LAN)
512 MB DDR
80MB Maxtor HDD and Samsung CD/DVD rewriter, connected via IDE (different busses)
nVIDIA-based AGP graphics card
PS2 mouse + keyboard
*NO* floppy drive

Killing aptitude seemed to get the installer running again, but left APT in a
broken state, so I started the install again from scratch, with the same
results. A search turned up bug 22225. Given this, I tried running the install
without the network cable plugged in, and it ran through fine. Once I'd logged
in to the installed system, sorted out the network settings, and added the
appropraite repositories, everything seemed (and seems) to be working fine.

The machine is connected to a wireless router (that also acts as a DHCP server),
which is in turn connected to my cable modem (from which it gets an external IP
address via DHCP). The firewall blocks incoming connections, but all outgoing
connections are permitted (using NAT, if memory serves). I was monitoring the
external connection throughout via my laptop connected to another port on the
router, and did not observe any faults or outage. I've not had any problems in
the past using Debian repositories, and as I said once Ubuntu is installed
non-networked and the connection set up after installation, it can access the
repositories with no problems.

If you need more details of something specific, or want me to try out some
variation or possible fix, I have a spare partition and so could reproduce the
installation procedure if neccesary - just let me know what you want.