OK it's the RAM. I've made sure to get matching sticks (Elixir ddr 400 pc3200 cl3).
However with either stick installed singularly in either slot 0 or 2 Linux boots fine, however put both sticks in (in either slots 0/1 or 1/2 configuration) and the linux boot fails.
Memory has a clean bill of health on 30+ minutes of Memtest. Windows is quite happy with it.

Whats really bad is that I've trashed my whole linux set up (software and driver installs, configs etc) when reinstalling 9.3, so I'm well upset about that.

However, theres got to be an answer (kernel params, BIOS setting [ no T2 dram doesn't work]) to make Suse run on 1gig of memory?

Have you tried the memory in slots 0 & 2? Have you been able to run Memtest with both sticks in the board?

Hi, yes that was my original configuration (0/2) and thats what I ran memtest against.
I've now got the the memory in (1/2), heres the output from Belarc
1024 Megabytes Installed Memory

Slot 'A0' is Empty
Slot 'A1' has 512 MB
Slot 'A2' has 512 MB

time to give up I think
I also tried ubuntu x64 live cd and that didn't like my config either.
Now I've got 60gigs stuck on a linux partition but I daren't mess with it as Grub is loaded there.

I'm not too bothered though as I've got plenty of other disk space and it seems faily stable. I'll use my linux from the fail safe boot from now on but it's only going to be used for trying out shell scripting for stuff I need at work, nothing else, it's just too unstable.