Visual Basic .NET Radio Buttons get auto-clicked

I was up until 01:20 this morning debugging code in VB.NET 2010. For hours I thought there was something amiss with my math or logic when a calculation in a secondary window which was affected by Radio Buttons kept giving an erroneous result.

The Problem – Visual Basic .NET Radio Buttons

At first I thought I was trying to use public variables in the wrong way and completely re-wrote the code only to get the same error. Eventually I found for myself by debugging with several breakpoints that when the secondary window was opened there was an automatic click on one of the Visual Basic .NET Radio Buttons (RadioButton1).