When I have a top level assembly up on the screen and if I want to open a specific part from the assembly on just Rc and open it from there. At that point usually I get another tab that cascades on top of the assembly tab in the Windows task bar at the bottom of the screen. I get as many tabs cascaded as parts I open. BUT sometimes when I open a part from the assembly the tab just switche3s from the assembly to the part and I only get one tab. It makes it a pain when I cannot go from part to part to assembly and back again just by selecting different tabs. I have to then go file open. What is happening or what am I doing wrong where sometimes I get multiple tabs and sometimes just one.