problem creating RAID1 volume with raidctl

I have a SUN Blade 2000 with an LSI 1068 controller inside.

root@sb2000:/ raidctl -l 3
Controller Type Version
----------------------------------------------------------------
c3 LSI_1068 1.07.00.00

There are two external disks attached over eSATA.

root@sb2000:/ raidctl -l -g 0.1.0 3
Disk Vendor Product Firmware Capacity Status
----------------------------------------------------------------------------
0.1.0 ATA ST31000340AS SD15 931.5G GOOD

root@sb2000:/ raidctl -l -g 0.4.0 3
Disk Vendor Product Firmware Capacity Status
----------------------------------------------------------------------------
0.4.0 ATA Hitachi HDT7210 A31B 931.5G GOOD


Now I'm trying to use the hardware RAID option, but no luck.

root@sb2000:/ raidctl -C "0.1.0 0.4.0" -r 1 3
Creating RAID volume will destroy all data on spare space of member
disks, proceed (yes/no)? y
Too many arrays.

I read, that this controller is limited to two arrays, but until now the
re is no array!

root@sb2000:/ raidctl -l
Controller: 3
Disk: 0.1.0
Disk: 0.4.0

Any hints what's causing the problem?