The bugs are similar. Bug 260725 says the window hides, but because the screen isn't refreshed fast enough on a non-composited desktop, you are seeing gray holes.
This bug actually says the window doesn't hide (on a composited desktop), which means either the snapshot window really isn't hidden, or the compositor is faster generating the snapshot, than hiding the window. In the latter case, it would be a KWin bug.
The bugs are similar. Bug 260725 says the window hides, but because the screen isn't refreshed fast enough on a non-composited desktop, you are seeing gray holes.
This bug actually says the window doesn't hide (on a composited desktop), which means either the snapshot window really isn't hidden, or the compositor is faster generating the snapshot, than hiding the window. In the latter case, it would be a KWin bug.