Anyone who has had the greyed out action bar issue on your hunter I found out that it may be related to certain pets. Apparently any pets that have the ability to stealth, when they go into stealth it causes a bug that is causing your action bars to grey out as if on cool down. If you change pets in go to one that doesn't stealth, the skills reappear off cool down and the issue should not return. Have tested on my wife's hunter with a non stealth pet and has not had bars grey out on her in 5 hours. Possibly stealth related issue.
Please help. Thanks!
I didn't find the right solution from the Internet.