[orca-list] XP-Like Ubuntu security question

[Glenn <glennervin cableone net>]

Hi,
I have been dissatisfied trying to get all the latest Ubuntu flavors to work 
on some of my older systems.
I have an ISO of XP-Like Ubuntu, version 10.04.  I also have the 10.10 ISO, 
but it seems that it did not work as well.
This works great with Orca, and it is using the Unity desktop, although I 
was able to log out and back in using:
sudo restart gdm
But my question is,
Since this is Ubuntu 10.04, is there really a security concern?
Or is it not just the latest stuff?
I am guessing that Ubuntu 8 is probably more secure than Windows 7, but 
maybe I'm wrong.
I'm just wondering what folks here know about the security of older Linux 
systems.
Thanks.

Glenn