Issues with EditorGUILayout, and GUILayout, after installing Unity4

I was writing a custom inspector in Unity3, when I updated the app to the newest version, my custom inspector began to behave strangely.

1. Any button when clicked doesn't change it visual state. yet it run the code inside my if-statement.

2. the values inside a intfield or floatfield, or even a textfield, cannot be selected, but can be changed, and if I keep clicking on it I receive an error: ArgumentOutOfRangeException: < 0 || >= this.Length Parameter name: startIndex

It's a error beyond my comprehension ... in Unity3 none of this happened.

EDIT: when I change the order of the components in the inspector it looks to fix the error 1.