Wireless problems with N600, WNDR3400

[gmartinez]

I have a Mac, which uses Mac OS X, Version 10.5.8. I replaced my Netgear wireless router (WGR614 v6) with the N600, WNDR3400.

My wired connection to the Mac works fine. No issues there.

But connecting my iPhone4 through the wireless connection is a problem. When I first set it up, it worked fine for a little while (10-20 minutes), and then one or more of several things would happen: 1) wireless connection became very slow; pages on Safari would take a long time to load, and apps would take a long time to update; 2) the SSID would not be found; 3) it would ask me to re-enter the password for the wireless network, but pages would still load slowly; 4) I sometimes would get an "unable to join network" message and it would revert to 3G.

I configured the router through www.routerlogin.net. I've confirmed that running the wireless network without a password appears to work fine. It's only when I use a password for the WPA2-PSK that I get this problem (wireless connection works fine for a little while then gets slow and quits).

Any suggestions? I've searched through this forum and found similar questions, but none of the solutions offered in those other threads have worked for me.

I did update the firmware. I don't know how to go back to the original settings.

Also, I didn't have this problem with the WGR614 router.

Thanks in advance.