2008 Volunteer question

Well, I was a volunteer at this most recent Anthrocon. The bulk of the time I volunteered was after the closing ceremonies, over in the Art Show as it was closing up. As it happened, once things were figured out, I think the time totaled some 16.5 hours or somesuch. According to what was listed, that would mean I'd receive a T-Shirt. Since things were already closed up when I finished, I couldn't receive the shirt there, and was informed that it'd be mailed/shipped/whatever, and I'd get it at a later point.

...Not a problem, except that not too long ago, about two weeks ago, I moved, away from the location I was living at for the time, and had recorded on everything that asked for it. I will not be returning to the same address. However, I have rented a Post Office Box within the same city, and filled out and completed mail forwarding through the USPS for what SHOULD be the same name and address that I filled out both my registration and volunteering form for AC with, though I don't know how it'd handle something that would be a package that wouldn't fit into this 3x7" box.

Now, I might be perhaps getting a little concerned over what would amount to nothing, but if it's the case that it might help things out, I wonder if it's possible to change the address here? I'd hate for that shirt to arrive at the doorstep of my old house, for more reasons than one.