CD playing intermittently

Hi
I have had a similar problem to this with my DVDs. Can anyone help?
I've burnt an audio CD using burnaware. The original file is an mp3.
When I tried to check the disc on my laptop it wouldn't work (VLC opens but doesn't play and shows no time length for the track) so I thought it hadn't burnt. Properties said it contained 0 bytes used and 0 bytes available. Odd.
Next time, putting the disc in the drive prompted itunes to open automatically and play.
I don't like using itunes to play so I thought I'd check file associations. I thought the file was was mp3, so I checked mp3 and the association is with VLC, which I like. So I checked the CD again and this time it says there's a 1kb file on the disc and it's a cda file.
I checked the cda file association and that's VLC too, so itunes shouldn't be opening and playing it by default, but that's another issue.
I just want to know why the file is sometimes there and sometimes not and why my mp3 has been replaced with a cda file. Nothing makes sense.
I have win7. I have had a similar problem with a DVD that I've burnt - sometimes doesn't play and shows empty, sometimes plays... Thanks.