I am having Sony DVD recorder, 8x highest recording speed. When I am burning cds with 8x or lower speed with Nero 7 ultra edition I got no problems but when I try to burn cds that have higher speed then 8x Nero couldn’t recognize it. Plz help?

That is usually caused when you select the DVD tab in Nero, instead of the CD tab.

It is not problem with that. When I insert any DVD disc with 16x recording speed it is recognised with my recorder but not with Nero.

Then update Nero.