My ISA server blocks the Wireless router

I have  the wireless router, The ip adress of Wireless router is for ex: 192.168.5.230. In Isa server 2006 this ip adress have given full access for internet.

in Wireless Router configured the DHCP as 192.168.10.10 - 192.168.10.199. There are 10 or more  clients connected to Wireless router.

But sometimes the Isa server blocks the internet connection ( this ip adress 192.168.5.230)  for router. the during of blocking 10 minutes or more. What's problem i don't know. I have try all variants of flood migrations confugiration.No Result!!