Imac 24" greasy substance when removing DVD's!?

[johny5]

I have never really used the dvd drive on my 2.8ghz imac as I have an external but I thought I should start using it. I had tried to burn disks before but they failed verification, I didnt think much of it at the time.
Anyway today I tried again, and the disk failed verification.
After removing the disk and looking at the surface there was a smeared mark of about 1cm square (ish) on the disk. When I wiped the disk to remove this greasy substance you can see that where the mark was, the laser hadnt written to the disk correctly and you can see where it hadnt burnt properly.

I tried inserting a new dvd nearly all the way in until the drive tries to grab the disk then pulled the disk out. You can clearly see that there appears to be something in the drive that is putting a greasy mark on the disks and it is smearing leaving a trail.

I am obviously going to call Apple tomorrow but I bought it online about 3 months ago. Really not happy with this AND the screen gradient issue (I could have lived with the gradient) but I paid a lot of money for this mac.

Anyone else know or had similar problems with regards the DVD drive?

I would love a mac pro, what do you think my chances are on returning this for a pro?

 

[johny5]

An update, I suspected it was the foam guide inserts inside the dvd drive or just as the disk enters the drive that was the problem so I smeared some Isopropynol alcohol onto a dvd and inserted so far in and out a few times.
That seems to have cleared it after it had dried.

god knows what it was!??