I have a problem when trying to add a second swap partition:

/dev-1# disklabel /dev/sd1b
# /dev/sd1b:
type: SCSI
disk: SCSI disk
label: Quantum ProDrive
flags:
bytes/sector: 512
sectors/track: 35
tracks/cylinder: 6
sectors/cylinder: 210
cylinders: 974
rpm: 3662
interleave: 1
trackskew: 0
cylinderskew: 0
headswitch: 0           # milliseconds
track-to-track seek: 0  # milliseconds
drivedata: 0 

8 partitions:
#        size   offset    fstype   [fsize bsize   cpg]
  a:   139020        0    4.2BSD        0     0     0   # (Cyl.    0 - 661)
  b:    65520   139020      swap                        # (Cyl.  662 - 973)
  c:   204540        0   unknown                        # (Cyl.    0 - 973)
/dev-0# swapon /dev/sd1b
swapon: /dev/sd1b: device not configured
/dev-1#

Does anybody know what the problem might be ?
(the disk is fine. I even have partition sd1a mounted)


	Stefan