Well, mystery solved.
Pinnacle Holdings emerged from Ch11 bankruptcy in 2002. Previous shareholders got warrants to purchase new stock. Now these warrants actually started trading at some point back then on a "when issued" basis, and with amazing foresight, I bought some. Then they became Global Signal, then bought out by CCI. Somewhere in the confusion the warrants became worthless and lost, then got posted on the pinkies last Dec, and started actually trading last week.