As with ur optical question, try updating the firmware of your disc drive, you can get them from the samsung website in the downloads section, I have had problems like this where drives just take a while to load up, all drives and disc's seem to load at dfferent speeds, don't worry about it.
To make sure your computer is gettin the right peformance, download cpu-Z and post some screen shots of your ram and cpu settings so we can see everything is runing at stock speeds.
To make sure your computer is gettin the right peformance, download cpu-Z and post some screen shots of your ram and cpu settings so we can see everything is runing at stock speeds.