With regard to the Belkin router, have you tried setting it up via a web browser?
Back up your current configuration to disk, just in case. Link up via ethernet and type 192.168.2.1 (which should be the default address) and try configuring it from there. I find it has no problems retaining any setting, including the administrator password.
I have found this router not to play nicely with Apple. Constant dropouts and connection problems. Plenty of similar posts on Amazon confirm this to be the case and Belkin's support does not get much in the way of compliments, either. I have the FD8233 revision, updated to the latest firmware. The auto update function does not work, you have to look for this on Belkin's site yourself.
One thing I did find, is that you cannot reimport your configuration settings after updating the firmware, so make a note of them first.