My vertical sidebar doesn't get focus/etc.
It implements IInputObject, but the IInputObject's methods never get
called.

I went to check OLE/COM viewer, and IInputObject doesn't show in the
interface-list as at all.
It also doesn't show under the list of interfaces implemented by my
DLL.

What could have caused this ?
I'm using IE6. On another computer with IE7, I see IInputObject
declared in iexproxy.dll, but IE6 doesn't have this file.
I tried re-registering shell32.dll but that doesn't help.