Can you post a (close up) picture of the DC input connection on your PCMCIA USB hub? Also, can you post a picture of the DC->USB cable? This would help.
What brand of USB adapter is it (any markings on the unit)? Did it not come with hookup instructions? Did it come with an AC/DC "wall wart"? Where does the AC/DC adapter plug in? Does the AC/DC adapter say "+5V" on it?