Nope. Safari Networking on mine is 0.0% , obviously nothing near your 99%so while running safari it has a helper running called safari networking it using 99 to 100 cpu even when no browser window is open. I have reported this bug. But i was wondering if any one else has this issue or if i am alone.
This fixed it for me but do you know what gets deleted with this cache?I tried deleting all my data from safari, but it didn't seem to fix it. I looked in the activity monitor to find out where the files the Safari Networking was hiding it's plists and I found them in:
I moved all the files to my desktop to be sure it was okay and It stopped the problem and now everything is back to normal. I deleted all the files since. Everything is working fine.
Sounds like a bad file stuck in your cached data. Hope this works for everyone else.