I shared similar experience.
M1.dll does not work under my SONAR Home studio (64 bit) mode with native VST (2.x) support. Then I tried Cakewalk VST wrapper - same negative result

. But Wavestation soft-synth seems to be OK.
I think Korg should take some actions on this issues - Wavestation works but not M1 !!
Howard Lau, Hong Kong
[Gigabyte EG45M-DS2H / Intel Q6600 / Emu 1212m / Vista 64 Ultimate]