samsung SH-B123L problems

Right ive had the samsung bluray internal drive for 11 months now (bought 25/01/2011 at ebuyer) and well for the past few months ive noticed a film destroying problem... while watching blurays via powerdvd it seems to randomly stutter and then eventually pause completely and after a few seconds (5 or 10) it will return with bit of lag and finally go back to a fluent film, the problem is that it doesnt happen with every film it seems random and theres no pattern to how frequent it happens or with what bluray disc.

What areas should i be looking into to diagnose this properly, need to do it soon as if it is the drive then need to send it back before warranty is gone!. Ive ruled out the discs as ive tried them on my panasonic bluray player and they work flawlessly. Ive tried looking for firmware updates (i did one when i first got the drive) but i cant find it anywhere on samsungs website anymore so if anyone knows the firmware update pages location id appreciate it as my model is missing :(.