Intermittent or random errors, usually point to a slowly dying power supply.
intermittent or random errors with a database/forum/hosting point to a PSU problem?
1.) most hosts have redundant power supplies.
2.) most power supply issues would effect more then just how quickly the apache server services web requests; you know, things like corrupting the memory of the apache process and therefore causing a complete crash.
3.) either way, it's the hosts problem if it turns out to be a PSU issue. Well, unless Nathan sent to server to the hosting company or something along those lines...
Anyway, hardware diagnoses don't usually extend to software very well.