Is this a virtualized server under VMWare or other? or standalone SUSE?
Been working with a site that is CentOS (virtualized) under VMWare and it exhibited rather strange behavior in that every hour from :32 to :37 minutes after the hour server was un-responsive. At first, 'client' said it crashed, but could still ssh into it. Could interact with MySQL (although it was slow). Looked and monitored for 6 days - found nothing. Finally convinced the virtual server administrator (VMWare) to check into the host OS. Yep, turns out there was another guest OS on that virtual server that was eating up all the resources on that server. Shouldn't happen but turns out another OS was given dynamic settings for space and memory - grabbed what it wanted when it wanted and at the expense of other guest OS's.
If it is crashing, many linux OS's will dump a .core file in the directory of the app when/where the crash happens.
If your server is not configured to do that, then this might help:
And a thought ... with a GUI desktop, apache/mysql services could appear to have issues when it's really the GUI or some applet left running, etc.. Could set your server to boot to command line only. Reboot and then wait.
'spirit of sharing', Ken