Roland system 1 and system 8 VST's only working fine without HT and MC

[Bonkhead]

Anyone tested/using roland's system 1 or system 8 vst's in Reason ?

On my i7 3770 (4 core, 8 threads) I can only make them work fine when hyperthreading and multicore is turned off.
They still even show 2 cpu bars with just one instance, but that's better than "computer too slow" messages when HT and MC are on.

Why is this happing exactly ? These vst's need to be caged inside a single core to work. Is this a Reason-is- just-beginning-to-host-vst thing which will hopefully be solved later on ?