When I was using Ubuntu 7.04 and then 8.04 x64, I never got any error messages what so ever. In fact, I would say Ubuntu 8.04 x64 is the most OS I've ever used, and have been in love with it.

Recently, I first tried to do an upgrade install from 8.04 x64 to 8.10 x64 using the update system and it would download files. The install was successful, but started getting the "Aperture beyond 4GB. Ignoring." error message, but also I/O error messages when seemed to be mostly about USB devices.

I also noticed 8.10 didn't boot as quickly as 8.04. I then did a clean [w/formatting partitions] install of 8.04 x64 LTS using a CD I got from ubuntu directly, and did a upgrade install from that w/out installing any programs. Same thing happened.  I then downloaded the ISO file for Ubuntu 8.10 x64 from ubuntu.com, checked md5sum, and tried clean install with it. Same thing happened.

Oddly, after then clean upgrade install, the Aperture error message at boot then said it wasn't big enough, but I don't remember the exact message.

The I/O error messages I would get after 'aperture beyond 4gb, ignoring', I didn't document them, and don't remember the nature of them, but I was getting multiple I/O errors, which seemed to be mostly about USB devices.

I gave up, and re-installed 8.04 x64 LTS from CD and continued using it. Didn't get any error messages at all from there.

More recently, I discovered Ultimate Edition 2.0 of Ubuntu x64 @ http://ultimateedition.info/
[a couple days later]; and decided to try 8.10 again.

I burnt a blank DVD after verifying the md5sum of DVD ISO file I downloaded for Ultimate Edition Ubuntu 2.0 x64 which is based off of Ubuntu 8.10 x64.

I also updated my BIOS from v13 to v16 for my abit AN-52 motherboard.

The BIOS update didn't seem to help.

However, one of the I/O error messages I noticed when booting was a message something to the effect of: "failed to enumerate usb device". So I disconnected the USB external IDE seagate HDD I use for backups.

After disconnected the USB EXT HDD, and updating the BIOS, I no longer got any I/O error messages or USB error messages.

What's odd about that, is I never have the EXT HDD powered on, only when I use it for backups from time to time; otherwise, it's always powered off.

So, after BIOS update and disconnect of EXT HDD, I installed Ultimate Ubuntu 2.0 x64 w/out error, just as I had done with Ubuntu 8.10; but Ultimate Edition 2.0 x64 seems to be at nearly the same speed as 8.04 did. However, Ultimate Edition was installed after the BIOS update, where my prior attempts at installing 8.10 x64 were before I updated the BIOS.

In any event, I still get the  "Aperture beyond 4GB. Ignoring." error message at boot, but at no time has that error seemed to prevent or hang boot, or OS once logged in.

The only BIOS setting that seems to have any relevance, is that the setting for "PCI-E relative items: [is set @=] maximum TLP payload size: "4096"..."

I have attached a text file with a lot of system info in it.

Overall, the BIOS update didn't seem to help much, but I never got any errors w/ 8.04 x64, and could leave my USB 2.0 EXT HDD plugged in, and not powered on, w/out any errors. I haven't tested it yet once booted up in 8.10, but will.

Hope it helps. Thanks!