I tried using the command:
defaults delete com.apple.safari WebKitDNSPrefetchingEnabled
....in a Terminal window to re-enable DNS prefetching and I got this message after hitting enter:
2013-11-18 20:21:24.479 defaults[359:507]
Domain (com.apple.safari) not found.
Defaults have not been changed.
Any idea what this means? Am I to assume that because of this error that DNS prefetching has not been re-enabled correctly?
No, I never did get an answer.........I kind of dropped the pre-fetching topic on my side because whether it was on or off, it didn't seem to make a tremendous difference on my browsing speed.
My browsing/page-loading problem actually ended up being something with my Comcast cable provider, and also an update to my antivirus software that I didn't notice come through that had an option defaulted to 'on' to check every URL on every web page against a suspecting phishing URL list. You can imagine the performance degradation from that AV option! So....I shut that AV option off and it dramatically improved my browsing speed overall, right back to where it was before.