Hi, I am fairly new to SketchUp. I am using an Intel base MacBook Pro 2.4GHz under 10.5.2. I have been working on a garage shed design with multiple layers, intersecting planes, materials. I have been experiencing more frequent hangs as the project gets more complex. The hangs occur using most of the tools particularly with push/pull, tape measure, rectangle tools. It seems to occur with trackball activity in changing the view. The entire system hangs with a spinning beach ball requiring a hard restart to escape. I can't tell whether my file is corrupted, the computer has an issue or I am just doing something wrong. Anyone able to shed any light on the issue or make some suggestions?