USB Ports reset when new connection is made with USB

I have a Seagate External 1TB HD that I use with my Asus GL502 laptop. When I plug it in, a notification comes up telling me it's been connected. Great.

When I plug any other USB device into my laptop however (like my logitech headset), the ports reset as if I've just reconnected everything and the notifications show up again, even though I never unplugged them.

This also happens to my mouse.....I don't understand. Please help?

This is most annoying when I am accessing a document or something important for school on the external hard drive, and after plugging in my mouse or headset, the doc/info I have open is no longer available and force closes because the laptop acts as if I've unplugged the HD.

note: this happens with flash drives as well.