As a tech here is what I know on this;
2.0 is backwards compatible, 1.x should work in it, the OS (Windows) needs the drivers for 2.0 from the mother board CD, or from the makers website. When using 1.x, devices will work at 1.x speeds just as if you were using 1.x ports.
1.x can not support 2.0 devices nor should they fit as 2.0 plugs are a little bit different, but the 2.0 jacks support both.
I hope this helps.
