heh... out of curiosity, I did this on a server that handles a site with 1.2 million raws and the rb4 trade script and there were 115 defunct processes at that moment.
Did a list immediately afterwards and there were 105 different different defunct processes (as far as I could tell).
I think your problem is normal. You either just noticed or just got a bump in traffic or just started running scripts
Hope this helps...