glows not doing anything

I'm working on another Narnia-inspired map and I've hit a problem.
The only river I want to have glows/blurs/Edge Fade Inner showing any glows -- at all.
I was working zoomed way in so I could spot the glow, and even putting really silly strength and blur settings (like 300 for both and colours like vivid purple) ABSOLUTELY nothing happened. I've also checked no layers were frozen, and there weren't any. It isn't essential, but I would like to have something to show that the river is in a steep gully.
Here's the image file and the .fcw
Comments
There aren't any rivers on "RIVERS Gorge" where you have the effect.
They are mostly on RIVERS.
With the really wide one being a gap between 3 polygons on the LAND sheet
If you want the rivers, or some of them, to have the effects on RIVERS Gorge you need to move those rivers to the RIVERS Gorge sheet.
This is all about sheets, not layers.
d'uh