Queue problem

i got 5 static agents on my TB,when calls increase, phones are calling at different times or not at all, CPU usege is low , i have ring strategy ringall, but if i am changing it to another strategy nothing happens,it doesn’t helps.when i am looking in ps where i have many defunct. processes dialparties.agi , asterisk and checkrecordings… does anyone know how to fix this problem? any ideas?