SRX5308 - VPN Problems

Serious issue here. currently after swapping an UTM25 at one site for the SRX5308 in it's place, a problem still persist with only getting 1/2 of the WAN bandwidth. secondly after transferring large packets of data across a vpn to the device, it shuts down externally, but works fine internally. even though all vpn tunnels are still established, there is no connectivity between the vpn(s) to this device nor can i access it via the web interface with the wan ip. i mean it completely shuts down external connectivity. i have already factory defaults this router initially when it had this problem with firmware 3.0.7-29, and now again with firmware 3.0.7-45; and just for kicks, i rebooted the router and tried sending 5GB across to it, and it shutdown 1/2 through this time...