I have saved bookmarks for about 30 web comics. When I open all the bookmarks in tabs, Safari 7.0.5 (Mavericks) will open the first 10 or so then give me an error on almost all the rest. It says it can't open the page because the server was not found. The behavior is consistent with the behavior described (with one exception) in this tech article:
Safari 5.0.1 or later: Slow or partial webpage loading, or webpage cannot be found
But unfortunately, following the instructions is no help. Switching DNS servers appears to work momentarily, then the problem returns. Disabling DNS does nothing.
I even re-installed Mavericks to see if it might be the Safari app itself (only way I know to reinstall Safari.)
No joy.
The problem is intermittent, with the one exception from the tech note, namely that once the error surfaces no amount of page refreshes will load the page. Otherwise, sometimes all pages load, sometimes only some, sometimes hardly any. Rebooting seems to work the same way changing DNS servers does, it goes away for a bit then surfaces again later. I can still look up and ping servers that Safari claims are unreachable from the terminal window without issue.
The only possibly related errors I see in the console are mDNS not being able to write to "clientPID (com.apple.webki) because of error" and that's not much help.
I'm at wit's end with this.