I have an ipad mini w/ retina 16gb wifi only. Since I have gotten it, the wifi has been spotty at best. I know it's the ipad because my imac and iphone seem to work fine when the mini just hangs when trying to load webpages. When it hangs, i can restart the ipad and it works fine. It is so annoying having to restart it all the time. If I use it a few hours, I'd probably have to restart every 30-45 minutes. I've tried restoring and setting up as new to no avail. Is this a known problem or should I take it in?