It’s because the PhoenixFD automatically start to render Maya fluids too (because it’s better then the default shader). We think to ship the Phoenix shader with the V-Ray for Maya, but since it’s still beta, it will not happen at this point… You must move the vray_phoenix.dll somewhere V-Ray can’t find it or install Phoenix to the other machines (you don’t need PhoenixFD license) and use it instead of the default shader. About the nightlies, the next successfull build of V-Ray for Maya must support Phoenix. Until then only official 2.1 and 2.2.