Some magic I don't need.
Knoppix 6.2.1 on USB; otherwise well-behaved.

Somehow, my 'minimize' operations have all become 'close' operations.
I click on 'minimize' and would expect a program window to shrink
to an icon on the taskbar. Instead, the program closes. Gone for good.
Happens for all programs with all window manager types.

Probably a configuration setting, but which one, and where do I look?