gotcha. I guess I need to get a new one before I break something. thanks!
It's not that you will break anything rather :
Any USB port must be able to supply 100mA of current to any device connected to it (at powerup). Any device can then attempt to negotiate more power, up to a maximum of 500mA.
A non powered USB hub can only draw 500mA from the port it is connected to, and therefore can only supply a maximum of 500mA total to all devices attached to it. If you have 4 devices trying to ask for more power, they will not be able to negotiate for more, the hub also needs to reserve at least 100mA for each port even if nothing is connected to them. Drawing more power then the 500mA total won't damage anything (since every device needs to be able to operate on 100mA, then ask for more power), you'll just get a popup saying "This port cannot provide power to all devices attached to it".
With an external power supply, the hub can provide the full 500mA to each of the ports (as it can draw the extra power needed from the wall socket, rather then needing to derive all of its power from the single port its connected to).
If you only attach lower power devices to the hub (keyboards, mice etc) you'll likely never hit the 500mA max. If you use a lot of higher power devices (external USB powered hard drives, some flash drives etc) you'll hit that max pretty quickly.