Hi, I got some messages asking if I fixed my LG burner and what I did, so I'll post incase any has the problem.
I don't know if this will work in everyone's case, but it did for me.
The problem seemed to me that I had the burner set as the slave CD-drive (which slowed down CD burning and caused it to burn the rings). As soon as I changed the drive to the master CD-drive the problem stopped and I can burn audio at 48 without any problems.
I hope this helps for any of you who might be having the problem with the rings under the CD. It's caused by the burner having to speed up and slow down during the burning process.