I'm wondering if anyone else is having this problem. I'm using SW2008 SP3.0 in a Windows XP system. When I open an assembly model of just moderate complexity(i.e. SW is using 400Mb of RAM), if I open a part model I will find that that window will sometimes persist no matter how many times I close it. In some cases, I'll get part model windows opening up all by themselves, and when I use the "Window" menu command to change windows, I get one of these "extraneous" windows. In other words, usually the extraneous window is one that I've already had open in the current session, but not always. The problem doesn't seem to be model-specific, although some part models seem to be worse than others. The problem seems to occur with part model windows only, in other words, I don't get extraneous sub-assembly windows. I occasionally noticed the problem in SW2007, but in 2008 it seems to be a lot worse. Anyone else? -Dave Adams