I encountered that problem in the tutorial flight that was pointed out for me in my thread Wanted: a tutorial flight here : http://www.captainsim.org/yabb2/YaBB.pl?num=1257412524.

Everything went well until landing when the C-130E didn't/couldn't catch the glide slope. The horizontal line was below the centre of the gauge but the runway lights were showing all red lights which tells me I'm below the glide slope.

I've done several flights from YMML (Melbourne) to YPDN (Darwin) and to other places and I never had any trouble with the glide slope there which is strange. The tutorial flight is the only time that I have had that problem.

Mark