well yes, if you reference this picture
then the two green ones with X14 on them are the polyfuses, The "X" is actually a manufacturers logo, and "14" stands for 0.14A or 140mA.
These are the ones.
The yellow device is actually a capacitor 47uF 10V which stores some electrical power so the power supply doesn't dip when you plug in a USB device (which normally also has a capacitor, which is empty when you plug the USB in, so it would temporarily cause a voltage dip if it wasn't for the 47uF elco to safe the day). The elco you can ignore, its only the polyfuses we are interested in.
If you have one polyfuse (its not actually clear from your description) which actually has a higher
value on it on one end than what is on the PI (TP1) itself, then it means that the HUB is actually attempting to put power back into the PI!
What I'm looking for is what happens when you do not connect the hub, but directly connect the USB keyboard to the PI, and then measure what is on the same side of the Polyfuse that you saw the 5.13 volt on (if you actually measured 5.15 V on a polyfuse lead then was it on the lower side or the top side of the polyfuse, I would like to know).
Also if you have an Ethernet cable ready (connected to your ethernet modem) plug it in to the (powered) RPI, and check if any of the ethernet LEDs start to burn, if not the "keyboard problem" might actually be a problem with the LAN9512 chip, which contains an USB hub, and Ethernet device. Some people have no ethernet, and no USB (checked with a serial connection) caused by a bad Crystal (X1) tapping it, or shocking it with cold or heat (soldering it) can get it going.