One way [and there is a BETTER solution on the horizon, with ST9] is to minimise the documents, so you can identify them for selected activating, or in your case, closing.
Design Manager Streetscape Limited
Solid Edge ST10 [MP0] Classic [x2 seats]
Sean, it took me some time to figure out just why I experienced this problem. And I discovered the reason accidentally. I had chosen SIVER as the APPLICATION COLOR SCHEME under SE OPTIONS/HELPERS. In this configuration, the MIN/MAX/CLOSE icons in the upper right hand corner that affect the individual files (not the overall software) are a pale yellow and nearly invisible. When I realized this, I went back and checked my records. I had previously used what is now called (and may've always been called) CLASSIC SILVER. In this scheme, the above icons are clearly visible.
For whatever it may be worth to others.