Hi tolia1010, welcome to CDF
You need a reader/burner that will support CD+G (karoke format discs).
What drive(s) do you have? Load up Nero InfoTool, and see whether the CD+G box is checked for it/them.
Quite a few drives support this format, not just Plextor (I use a Samsung SH-S162L which supports them).
So just let me know what your drive(s) are.
Also, if you don't have it, CloneCD is good for backing them up
Edit: InfoTool screenshot: