hldsupdatetool.bin won't execute

[Vicpop]

Here's the story:
I install the latest Ubuntu Server Edition (8.10), for the amd64 processors (I run a Core 2 Duo).
I recompile the linux kernel (for the whole 1000fps deal).
I download hldsupdatetool.bin, copy it to a srcds folder;

Code:

joe@ubuntu:~/srcds1$ chmod +x hldsupdatetool.bin
joe@ubuntu:~/srcds1$ ./hldsupdatetool.bin
-bash: ./hldsupdatetool.bin: No such file or directory

Now, there's no error when I do chmod, and the color for the file changes from plain grey to a bright green when I check through ls.
Am I doing something stupid? I have installed ncompress (wasn't installed by default), and there's no difference.

If I can't get this fixed by Wednesday (day before L4D demo) I'm gonna have to just revert to vanilla Ubuntu 8.10.

[css]

Hmm.. why did you install AMD64 optimized version if you have Core 2 Duo? AMD's got X2 and Intel's got C2D.

Anyways, if it isn't that, then maybe it's missing 32 bit compatibility libraries.

Did you try to run it before you reinstalled kernel?

[Vicpop]

http://en.wikipedia.org/wiki/Amd64
AMD renamed x86_64 to AMD64. It's just 64bit, the processor architecture is the same, afaik.

And no, I didn't try setting up srcds before I reinstalled the kernel, because I wanted to have a clean install of the new kernel before I did everything else.
..Might've been too soon to do, but I'm setting up CentOS 5 right now..

[css]

If you're running for 1000 FPS, then read this: http://forums.srcds.com/viewpost/47667#pid47667

Ubuntu Server edition does 1000 FPS without kernel re-compile.

[Vicpop]

Okay, I reinstalled ubuntu server edition-- did the linux-rt thing instead of recompiling the kernel.
Still won't execute. Same problem.

I've been searching around, and I came across this: http://www.kalamazoolinux.org/mailarchive/9811/msg00019.html
I'm not sure what to think about it.

EDIT: This is really weird; I tried installing 8.04.1 instead of 8.10 (I'd gotten an install working a long time ago), but it has the same problem.