Thanks everybody for the input.
@mindbomb: Tried the nightly with the same results.
@KoD: I've tried rolling back to an older version and it also does the same thing, however Haali works fine on my system.
@CoRoNe: Yes I'm aware, however my problem is not with the decoder, but solely with the splitter.(my system will "brute force" the decoder fine in any case).
Playing around some more I've realized the stuttering only happens with original optical media and
ONLY with the LAV
Splitter in the chain, regardless of the decoders used - and yes the media is decrypted.
If I use MPC's internal splitter with any combination of decoders,
including the LAV A/V Decoders, the media plays back flawlessly.
So is the LAV Splitter not capable of reading optical media in real-time or whats up? Seems odd when MPC's internal splitter does it without any issues.