Why don't you try using a conversion program to convert the MP3s to WMA or WAV then back to MP3 and see what happens?
If that doesn't work try using a different program. What type of MP3 player do you have?
You can always just keep doing what you are doing now because CD-Rs are fucking cheap.
Or you can just download MP3s off the net once you legally purchase them it doesn't matter how you get copies of that song.
I own Hypocrisy - The Arrival. If I go and download a ripped copy off the net it doesn't matter because I still own it.