Alpha Glow and Drop Shadow having no affect

Forthe last fre days I have been cutting a number of sequences using images.  For eatch ImageI apply a Alpha Hlow and Drop Shadow effect.  The Alpha glow is to put a thin black line around the image ot give it a small border.  I have saved these two effects as presets and have used them around a hundered times and they work fine.  I now add to 4 new images in a timeline and  they have no effect!.  Ive tried reapplying them and even copying them from another image they worked fine with (and still work fine) not vant get the effects to have any affect.