PS3 - Wireless network problem

Question

Got PS3 & netgear router. Get logged on to network ok and can browse the store etc but when I try and go on line it get kicked as server times out or loses connection.

Managed to play motorstorm once online in about 50 attempts. Other games also die on me before I get it. I have also checked and there is no ip address conflict.

Netgear have opened all the tcp & udp ports that sony publish should be opened and I manually reset the ps3 settings ip address etc just in case the scan was not working properly.

Sony said get netgear to set a DMZ outside the DHCP range and then call them back to set something but Netgear said this wouldn't work and would leave my computer open to attack !!

Quickly losing the will to engage with technology ! Please help !