I have tested this again with LWJGL 2.9.0. The behavior of the bug has changed a little - it has now a ~95% reproducing chance. I'm wondering why this bug has a different behavior on different versions: 2.8.1 is working fine, 2.8.3+ has a ~10% reproducing chance and 2.9.0 has a ~95% reproducing chance.
In this case it is a disadvantage that Minecraft is not free. If somebody of you would be able to test this it would maybe easier to say if it is a Minecraft or LWJGL bug.