The latest plug-in seems to be borked for Mac. I read somewhere about using version 1.0.9.51. Found it with a Google search. And I can now access remotely on the Mac (must be in 32-bit mode; done by holding down '3' and '2' at boot). For the moment, this is only tested on Snow Leopard (works) and Lion (does not work in either 64 or 32-bit).
This info may be readily available elsewhere. But I had to search long and hard for it. Hopefully, anyone in the same circumstance will benefit from a quick(er) search result:)
