Yes, this is the problem. The last SL viewer version (3.5.0) does not run on a Mac with this configuration: Procesador 2 x 2 Ghz DUal-Core Intel 3 GB 667 Mhz DDR2 FB-DIMM NVIDIA FeForce 7300 GT 256 MB Mac OS X Lion 10.7.5 What can I do? thank you verymuch