We don't have any specific reports on that *specific* router, but there have been problems in the past with Linksys routers doing similar things.

The first thing you should do is make sure you have the latest firmware for your router.

If that's not an option, or it doesn't help, then you can change the settings in PingPlotter so it waits between sending packets. See here for details:

http://www.nessoft.com/kb/22

If none of that helps, feel free to post back here with what you've done and we'll see what we can do to help.

- Pete