Cisco WAN :: RV082 V4.1 Internet Hang Until Cold Restart On Dual WAN?

I am having issue with a RV082 with firmware:

v4.1.0.02-tm (Sep 16 2011 18:40:48)
 
On setup 1 I have;Using 2 WAN, 1 from fiber 5mbps symetric fixed public IP and other is DSL private dynamic dhcp address 3mbps/900kbps

 On setup 2 i have:Using 1 WAN, from fiber 5mbps symetric fixed public ip Both router have exact same firewall configuration, subnet and port forwarding and we have the seccont backup DSL coming in a few day for setup 2.on both setup, the RV082 is the main internet gateway/firewall for a set of server...
 
Setup 1 work perfectly and been online for 2 week (since install) without issue
 
Setup 2 worked for 2 day then had to reboot, then work for few days then need reboot, now it look like it need to be rebooted every day. the internet just stop working and a simple reboot does the trick... also, when that happen I can stil remote in server that have port forwarded in the router or connect to router management port, but internet on the server is down... I tried opendns and google dns on both WAN connection and still no luck.I have followed instruction on various support forum;

-more reliable dns server
-lower MTU
-failover vs load balance
-disabling SPI and DoS protection
 
at this point I'm about to swap both router to see if it not a defective hardware or disconnect DSL WAN on setup 1 to see if its more stable but the whole point of installing this router was for Internet redundancy which so far dosent work as expected.