So I've searched thru as many Bass libraries as I can and although there are a lot of Slap Bass sounds, there just doesn't seem to be anything like a simple fret click. This is the sound made by playing the strings hard with fingers and slapping the string down against the fret instead of sort of 'picking' or strumming.
 
Don't know if this makes any sense. Any ideas on how to produce this? I have Dimension and Rapture, plus Kontakt 4 and SampleTank, PPG wave 3.v...
 
This sound, as used by Steve Harris, is excellent for bringing definition to the rhythm the bass is playing - really cuts through any low end mud