Couple questions:
1. Is it around 10, or exactly 10 devices? Does that include wired?
2. How do you get the devices back online? What is your process?
3. When you loose it on one wireless, do you loose it on all at the same time?
Things to try:
1. Check your DHCP IP Address Range(Setup>Network Settings), it should be 192.168.0.100 to 192.168.0.199. Also, if you have static IP's set, make sure they fall within this range.
2. What is Subnet Mask set to(Setup>Network Settings)? Should be 255.255.255.0. Unless your range is larger then a 100.
3. Do you have any Mac filtering turned on? (Advanced>Network Filter). If so, turn it off.