too deep for your wall?I'd have my doubts about that.What sounds more likely is your not drilling the hole deep enough.I'd guess your trying to fit rawlplugs, which are expanding ,into plaster.Small wonder your rail keeps falling down.If any thing the plugs need to be longer(red or brown) and longer screws to hold it.Rawlplugs are for fastening into brick/stone,or concrete,not plaster.
caine, September 2008