Which is the persistent problem? The favicons disappearing randomly should be fixed as of rc1--let us know if it is not.
As for flushing the cache while saving the favicons, you can do that now manually. Just quit OmniWeb, go to ~/Library/Caches/com.omnigroup.OmniWeb5 and delete everything inside except the "Page Icons" folder.
As for flushing the cache while saving the favicons, you can do that now manually. Just quit OmniWeb, go to ~/Library/Caches/com.omnigroup.OmniWeb5 and delete everything inside except the "Page Icons" folder.