4 USB 2.0 (4th shared with eSATA port). Did you connect to the shared port or one of the other three?
the above statement took me by surprise.... so i checked the documentation.
According to this doc
http://h10032.www1.hp.com/ctg/Manual/c01913253.pdf
the shared eSATA/USB port is No 6 on the left side components while i was connecting the mouse to No 3 on the right side components.
So, the answer is NO. I was NOT connecting to the shared port. I was connecting to one of the other 3.