Give samsung tech support a call. It is an interesting issue. Are the movies legit? Some opticals won't run some movies...HDCP for example..can cause some rightful issues. But if the discs are legit, this is certainly an issue you need to report to samsung.
Make sure you have your reciept, if possible a fax to send it in, and the disks you cannot use to hand, along with thier product descriptions, so that they can be matched for research into the issue itself.
You'll need the items Serial number and model code, which will be on the item itself as well.
You may be referred to a specific service centre to resolve this.
I hope this is sorted out for you.