im not sure that i understood exactly what you mean, but when minimizing the playlist in winamp it only changes the height property...

add this code to your program in the event where the button is pressed, and change '100' to what the small size is, and change '1000' to what the large size is...(the form must have one of those sizes at startup).

VB Code:
  1. If Me.Height = 100 Then
  2.     Me.Height = 1000
  3. ElseIf Me.Height = 1000 Then
  4.     Me.Height = 100
  5. End If