asterisk users - May 2004 - asterisk cpu load

Hi !

Running asterisk (cvs 20/05/04) with config
intel 2.4GHz(no SMP); 1GB RAM; 1*E100P; IAX1 slinear; RH 9-2.4.20-8(no
patches)
When running load (30 simultaneous calls), the server utilizes approx
10% CPU, but every 20-30 seconds it's a short peek where the
asterisk-process takes 99% CPU. 
Have searched the mailing-list but not found any explanation/solution to
the CPU-load peek... 
Can anybody advice me here ?

Br / Jan Terje T?nnessen