Wifi b/g phone connects to hotspot but winbox cannot ping it

I have UTStarCom F1000 G which works well with Linksys G on using WEP key i can make calls. However on my Mikrotik hotspot, it registers fine but all outbounc calls fail. It assigned an ip by the hotspot but i cannot ping it from winbox.

Ive enabled login by MAC, Chap & PAP. I’d like this wifi phone to authenticate by MAC only and enable the MAC address in the access list. How can i achieve this?