ActionScript 3.0 :: Error - Null Object Reference When Creating A Static Variable

Basically I have 2 classes, A and B. B derives from A. Inside A, I declare a static variable/constant to the class of B. When I run the program, I get a null object reference error, with the line pointing to the class declaration of B, i.e.

Code:
public class B extends A

For reference, these are the 2 classes:

Code:
package
{
public class A
{

[code]...

Also, this error only occurs when the variable is static. If it's just a normal variable it works fine, i.e.

Code:
private var OTHER:Class = B;

If I change the static variable to point to a different class, it's also fine, i.e.

Code:
private static var OTHER:Class = Main;

I can probably work around this, but it's a bit of a pain in the ass. Anybody know what's causing it, or is this a Flash bug?