I've updated the SplitButton control to paint the Image property, plus I've added ImageAlign and TextAlign support. I've also fixed a dozen other little bugs, and code signed the dll file.
The reason I had left the Image property unimplemented was because I thought "who needs a car any color other than black?" It turns out some people do. If you have any comments, bug reports, or general chit-chat leave a post on the forum. (No registration required)
Download SplitButton v1.6 [includes SplitButton.dll and the C# source files] It works with any .NET 2.0 or above language (C#, VB.NET, etc.)