I'm running into an issue where the wireless network I'm working on is going down after about an hour. There's about 4 hard wired computers, 5 wireless computers, and some iPad's that are only used about once a week, but after an hour at any time and with any traffic (including only one person being on the entire network at all for that entire hour) the wireless computers will all show that they are connected, but you cannot connect to the internet nor the network files. All hardwired computers are still working properly. We have replaced the router twice in the same month, but to no avail. This only started happening about 2 months ago (no changes in our setup). Any ideas?