Answer for router help
Based on what I read, it seems that this particular model had some issues with early versions of firmware. I would make sure that your router has the latest firmware available. If not, upgrade it then test again. If you do have the latest firmware, then perhaps the router is malfunctioning and you simply need a new one. However, you will want to test a wired connection through the router with no other computers connected (which means you will need to turn off wireless or at least change the wireless network name and/or password to make sure no wireless devices are connected to skew the results).
Let me know what you find.