Don't load shaders when VBOs are active

Just don't. There's no rule against this, but watch out for it because it will cause random crashes on some hardware...but not all.

Really? I had the strange bug that some shaders where only loaded 1 of 2 times when VBO's where active, but never crashes...

In other breaking news, do not get into your microwave with your hotplate. More on this, at seven.

I will keep this in mind, ty.

By active you mean loaded and selected as the source of geometry and called by some gl function to draw with them? Are you saying you can't use shaders with vertex buffers at all?