Button shortcuts invoked without Alt
I have a fairly complex .NET form in which one UserControl contains some buttons and another UserControl. The inner user control accepts all keyboard input (IsInputKey is overridden to return true always). The buttons support keyboard shorcuts (for example the Skip button's text is "&Skip" to make Alt-S a shortcut for clicking the button).
However, when the inner control has focus, typing a plain "s" invokes the Skip button function instead of entering an "s" into the text of my control.
A breakpoint indicates that the skip button function is being invoked directly from .NET framework code. My IsInputKey function is being called as expected.
How can I prevent this behavior?