[ioniamsa]

I have found the solution accidentally. I had problems with httpd also. As it turned out one library was missing. Apache did write its problem into the event log:

org.apache.httpd[21227]: dyld: Library not loaded: /usr/lib/libpq.5.dylib
org.apache.httpd[21227]: Referenced from: /usr/sbin/httpd
org.apache.httpd[21227]: Reason: image not found
com.apple.launchd[1] (org.apache.httpd[21227]): Job appears to have crashed: Trace/BPT trap: 5
com.apple.launchd[1] (org.apache.httpd): Throttling respawn: Will start in 10 seconds
ReportCrash[21216]: Saved crash report for httpd[21227] version ??? (???) to /Library/Logs/DiagnosticReports/httpd_2011-08-28-003002_localhost.crash

A closer look confirmed that '/usr/lib/libpq.5.dylib' does not exist but I had '/usr/lib/libpq.5.3.dylib'. Making a symbolic link solved my problem:

sudo ln -s /usr/lib/libpq.5.3.dylib /usr/lib/libpq.5.dylib

This also made OmniFocus work again!

The cause is probably postgresql 9.0.4 installer (dmg), I am not sure though.