M4P to MP3 conversion freeware?

I am unable to burn mp3 cds from itunes even though I own the original cds and ripped them into my library using itunes. I think I would have to re-import them using mp3 encoder settings. I know there is software that creates a virtual cd burner and burns a virtual wav cd on your hard-drive, then allows you to burn a mp3 cd from the virtual drive. Those programs cost about $40. Is there any free-ware to do this? Should I change my itune settings so it no longer burns m4p(aac), but mp3 instead? Is there a disadvantage to mp3 versus aac?
Thanks!

Sorry, I'm a little confused. Are you trying to burn a cd from mp3s or mp4s? If you're having problems with mp3s, convert them to mp4 in iTunes (right click a song and choose "Create AAC Version").

Do you get any error messages?

Lets step back in this. M4p are protected aac files, meaning they have DRM applied and while this is defeatable, this is not (I believe) an acceptable topic of discussion here.

Next, why can't you burn mp3? It's an option once you click on 'Burn'

Thanks Mike. I selected the mp3 option, but itunes would not burn the mp3 disk (due to drm issues). I think it is because when I originally ripped the cds, itunes created m4p files with drm. I can understand if I purchased the files from itunes with drm, but these were cds that I own.

iTunes won't rip and create DRM, that's only applied to iTunes Store songs that I'm aware of. They should be m4a ?

re-rip them from the CDs, after setting MP3 as the import format

odd, since iTunes doesn't add DRM to ripped tracks

The songs I bought and the songs I ripped are all m4a files? I did find a tab in itunes that allowed me to make an mp3 version of a tne i bought on itunes. I don't understand why it allows me to make an mp3 version but not burn an mp3 disk. I'll just re-rip a disk with the mp3 setting and try to burn it as an mp3 disk.
Thanks everyone!