Is there a reason you are updating FW? Is there a problem?
Lets figure out the problem before updating.
What HW version is your router?
What FW version is currently loaded?
What ISP Service do you have? Cable or DSL?
What ISP Modem do you have? Stand Alone or built in router?
What ISP Modem make and model do you have?
Ensure DNS IP addresses are being filled in under Setup/Internet/Manual?
Turn off QoS options.
Turn off Advanced DNS Services if you have this option.
Turn on DNS Relay under Setup/Networking.
Setup DHCP reserved IP addresses for all devices on the router.
Ensure devices are set to auto obtain an IP address.
Set Firewall settings to Endpoint Independent for TCP and UDP.
What wireless modes are you using?
Try single mode G or mixed G and N?
What security mode are you using? WEP, WPA or WPA2? Preferred is WPA2.
What wireless devices do you have connected?
Any cordless house phones?
Any other WiFi routers in the area?
Turn off all anti virus and firewall programs on PC while testing.
Turn off all devices accept for one wired PC while testing.
I am having problems uploading the new firmware. Can someone help me? This is the message I got when I try to upload. 
Upload Failed
The uploaded firmware file may not be correct. You may have uploaded a file that is not intended for this device, or the uploaded file may be corrupted.
If the uploaded file is correct, it is possible that the device may be too busy to properly receive it right now. In this case, please try the upload again. It is also possible that you are logged in as a 'user' instead of an 'admin' - only administrators can upload new firmware.
The Gateway will not be reprogrammed.