[jp] can't sync: "pi_bind error: /dev/pilot No such file or directory"

I don't think I changed anything on my computer, but I can't sync anymore.

The only change that I can think of is installing pilot-xfer.
When I press the sync button on jpilot, i get:

pi_bind error: /dev/pilot No such file or directory
Check your serial port and settings
Exiting with status SYNC_ERROR_BIND
Finished


The USB cable is plugged into the computer, and the pda is plugged
into the usb.
the j-pilot i'm using is version 0.99.9-pre2

help.