Panic on boot

[Meaghan Hayes]

When I try to boot FreeBSD, it cycles through all of my hardware etc.
as with a regular boot then says:

panic: ohci_add_done: addr 0x7fef16d0 not found

and tells me that it's rebooting, and just keeps doing this.

I was told that it was most likely a USB issue, especially if I had
recently added any new USB devices. I unplugged all USB devices on my
box and still recieve the panic error.

Help is much appreciated!

-Meaghan Hayes