Web development - to stop the website maxing out the CPU

We had a new site built [login to view URL] in prestashop in September and as soon as it was lunched we have had massive [login to view URL] further investigation we noticed every now and then it was using 100% of the cpu and 100% of the [login to view URL] then agreed after looking in the forums we needed to have the site upgraded to 1.4.9.0 Because the older version was known to have bugs that could make this problem [login to view URL] did not fix it so we changed over to a dedicated server with lots more power. Double the ram so now the ram is using 75%. This did not fix the cpu issue. Top Processes User Domain % CPU Process wonderla [login to view URL] 94.3 /usr/bin/php /home/wonderla/public_html/[login to view URL] wonderla [login to view URL] 93.8 /usr/bin/php /home/wonderla/public_html/[login to view URL] wonderla [login to view URL] 92.5 /usr/bin/php /home/wonderla/public_html/[login to view URL] version 1.4.9 with custom template (attached) with SSL Server snapshop(WHM):[login to view URL] PHP info;[login to view URL] Server info:MySQL version : 5.1.65-cllArchitecture: x86_64Perl version: 5.10.1Apache version: 2.2.23 Please can you take a look and fix this??