Found the MacMiner entry in library/applications folder and deleted it.
It now loads but will not authenticate.
I have switched OFF the Firewall on the Mac .
The pool and user credentials are OK. I use them with my Gridseed and Rasberry Pi the whole time.
I also tried scrypt coins, with the same authentication error, but I want to mine x11 coins with the Mac's CPU.
[2015-04-15 10:55:13] 2 miner threads started, using 'X11' algorithm.
[2015-04-15 10:55:13] Starting Stratum on stratum+tcp://pools1.cryptopia.co.nz:5094
[2015-04-15 10:55:13] Binding thread 0 to cpu 0
[2015-04-15 10:55:13] Binding thread 1 to cpu 1
[2015-04-15 10:55:15] Stratum session id: deadbeefcafebabefa00000000000000
[2015-04-15 10:55:16] Stratum difficulty set to 0.001
[2015-04-15 10:55:17] Stratum authentication failed
[2015-04-15 10:55:17] ...retry after 30 seconds