Occasionally, I get part of an application lingering behind on my desktop:
This is part of a context menu for an application. It is always top-most, meaning that it is always on the screen, and I cannot click on it (it just clicks through it). It has happened before, sometimes with whole windows. It remains on screen even if the application it originated from is no longer running.
How do I get rid of it without rebooting?
Solution:
I’ve found a really easy hack to get rid of context menu phantoms like what you describe. Simply go into your screen resolution settings and change to a different resolution, then change back. The change of resolution seems to reset stuff at a lower level than where the phantom exists, which means the phantom gets cleaned up during the resolution change.