1. make sure 2nd editbox is enabled
2. enter some text in it
3. go to options under +display -> options -> visual styles button
4. change anything
5. click ok, ok
The text you entered in the 2nd editbox should be cleared. Doesn't apply to default command, if you have one set, and set to show it, but anything after the command is gone. It seems to clear the 2nd editbox of all windows.
mirc 6.16 on windows xp sp2