High CPU load on 64bit architecture only?

[Roland Alton-Scheidl]

A user has successfully compiled kvats on linux amd64 gcc 4.3.1 with some 
script changes, see
http://www.kvats.net/cms/component/option,com_fireboard/Itemid,29/func,view/id,40/catid,12/lang,en/

I use kvats on a 64bit Intel Duo processor (still compiling with gcc 4.2.3).

I share the experience with that user, that the CPU load goes up to 100% under 
following conditions: 

- after hanging up a call
- second call coming in
- putting call on hold
- playing file from jungle

Has anybody else similar observations? 

--Roland