iMac disconnects from wifi when iPhone 5 connected?

The answer to this question is "yes" - at least for me.

Not sure why, but I'm guessing it would have something to do with the iTunes/iPhone settings, but I'm not entirely sure.

If I start the computer with the iPhone connected, the wifi connection is established but after a few minutes it disconnects. I have to turn the wifi off, and then back on, for it to establish a connection. To which it disconnects again after a minute or so. This will repeat for quite sometime. Sometimes it will finally stick after repeating the steps several times... often more than 10.

BUT - if I completely disconnect the iPhone, then the connection sticks.

I did a quick search but didn't find something echoing this problem. Anyone have any thoughts?