This is because apache, by default, compiles in a modified version of expat (called expat-lite) that differs from the normal expat, which perl's XML parser module uses. Having two different expat's in memory is enough to segfault the apache child. You will see this behavior when running cron with 'op=cron' or re-fetching the RDF feeds from the RDF admin tool. Sadly, the only way to fix this is to recompile apache.
See section 2.1 for an explanation.
See the question above; this is most likely happening when Scoop's cron tries to fetch RDF files.
This means that somehow either Apache or Scoop is failing without warning and just stopping.
If Scoop was working before and is now giving you ``Document Contains no Data'', it may be because Apache has run out of space to write its log files. Scoop has been known to trigger this via its page caching (4.18), if Apache's log files and Scoop's cache files are on the same partition on the hard drive.