puhh then im out of ideas it sounds crazy nothing impossible though in it(c) different systems different complexities and possible factors for issues, not sure but one last possibility would be in the bios itself looking for gfx related options, though the bios is optimized by the vendors and mostly not changeable @ all on Mobile platforms, dunno about your system
So in the end you might need to contact the Laptop/Notebook vendor and bring in your issues and ask for Help (though he most probably will reply with something like "it can work yes but it's unstable and never was a advertised feature we only advertised 720p playback so we see no reason to support you in your efforts to make it work"
).
Does lower resolution bitstreams playing fine you only have problems with Full HD 1080p and only Interlaced or also with progressive 1080p streams ?
And you can watch that whole Blu-Ray with full Hardware acceleration and without issues but only 1 time after driver installation or are the acceleration failing problems already appearing while the 1st playback ?
Another option you would have if you still want to use Hardware acceleration would be a external Decoder DSP like a Broadcom Crystal (also Splash Player supports it)l if you have a Mini PCI-E slot free for it