Just to share. My box went two times in three days out of memory hard crash (no keyboard response). So far, I have found that enabling system mootools upgrade at Joomla + Webiya toolbar was having an immediate impact on server load values. Data Center did a Hardware check for me, after those two crashes and hardware is ok.
The server run on dual xeon 2.4ghz with 2GB RAM... RHEL 5.5
Just sharing this. It is unfortunate since I liked very much the webiya toolbar.