We use a muxlab blaun to run 2 projectors using cat5 cable. The blaun works perfectly if we hook it to a PC, but when we hook it to the iMac using a mini dvi to vga adapter we do not get a display. We can hook a single projector that sits right beside the iMac to the same mini dvi to vga adapter and it works great. Any ideas? will the blaun work with iMacs?