iMac scratching discs while burning?

[mgridgaway]

Hey all,

I was burning a few discs the other day and noticed that my iMac is leaving ~1cm curved scratch marks around the middle of the disc (ie, about equal distance between the hole in the middle and the edge). It won't do it every time, but I'd say about 50%. Anybody have any clue what's causing the scratches?

[MultiFinder17]

Something is misaligned inside; it happens from time to time with the slot loading drives. I'd take it to Apple and tell them, if it's under warranty, they'll fix it.