Extremely High Server Load... Out of the blue

Hey, just posting because nothing I do seems to help... I have a machine running a Celeron 2.4Ghz 1G Ram server on Fedora 4. Running Cpanel/WHM

This server has one large forum site, and one or two small no-volume sites... I have checked stats and nothing has increased, still the same old stats that these sites have all had for a month or two now... the large site has 50,000 page views per day on a PHPNuke type / PHPBB forum site...

The server load USED to be 0.2 to as high as 1.2 and it fluctuated through the day... and the server was very snappy and great... But then about a week ago suddenly my serverloads are fluctuating from 4.0 to 6.0 and even at spikes it breaks 10.0 now... I have tried optimizing apache, and mysql... can't find the problem... I don't know what is causing so much slowdown on the server...

This server had many things installed and such during last month, but all of them minor opensource php website packages, not serverside stuff... The only change to apache I made in the last month was turning on GD, and Zend (for one of the opensource things, but I didn't end up using it at all). Other than that the increase just appeared overnight (so I thought it might have been a cpanel auto update)

Any help would be much appreciated... I planned on selling space on this server, and I can't do that if it is running like garbage with a mere 50,000 page views... that isn't that much volume really (this site ran this smooth on my old P3 500 dual processor with 512MB Ram... which also had 300 other websites running on it... so you can't tell me the server can't handle it...)

Thanks!