Android Phone coecting to router cause timeout of other devices

I'm having a very weird problem regarding my wireless router. I bought it a month ago (it's a TPLink, model TD-W8960N) and everything was going fine, until today, weh I got home, I coected my phone to it and after a while I noticed it was literally blocking my mac from coecting to any page. At first I thought of an IP conflict problem, but my router is solving IPs properly (phone is like 1.101 and mac is 1.103, and there's a chromecast coected as well). Then I just pinged from my computer Google's DNS while i was tuing off and on my phone's wifi and,as you can see from the screenshot I've uploaded here: http://imgur.com/fKp7498, the moment the phone coects to the router, the pinging goes in timeout request, and only a very few packages are delivered a while later. I have to specify that no change was made both to the Mac and my phone in the last week. Also I rebooted all the devices several times.

I did some research on my own but I found no answer, so I'm addressing to you since I am quite a newbie in this sort of tasks. Do somebody have any idea of what's going wrong?