RHEL5.5 the mtx (mag. tape/changer) command doesn't recognize new LTO-5 drives in library

Issue

• two HP LTO-5 drives installed into an existing Quantum Scalar i2000 library which already had 11 of LTO-4 drives

• mtx command is not recognizing the addition of the two new drives.

• tapes have /dev/sg* associated devices
• loaderinfo command shows the correct number of elements

# mtx -f /dev/changer status

  Storage Changer /dev/changer:11 Drives, 90 Slots ( 18 Import/Export )
Data Transfer Element 0:Full (Storage Element 2 Loaded):VolumeTag = 104132L4
Data Transfer Element 1:Empty
Data Transfer Element 2:Empty
Data Transfer Element 3:Empty
Data Transfer Element 4:Empty
Data Transfer Element 5:Empty
Data Transfer Element 6:Full (Storage Element 4 Loaded):VolumeTag = 104018L4
Data Transfer Element 7:Empty
Data Transfer Element 8:Empty
Data Transfer Element 9:Empty
Data Transfer Element 10:Empty
      Storage Element 1:Empty:VolumeTag=
      Storage Element 2:Empty:VolumeTag=
      Storage Element 3:Empty:VolumeTag=
      Storage Element 4:Empty:VolumeTag=

# loaderinfo -f /dev/changer
Product Type: Medium Changer
Vendor ID: 'ADIC    '
Product ID: 'Scalar i2000    '
Revision: '607A'
Attached Changer: No
Bar Code Reader: Yes
EAAP: Yes
Number of Medium Transport Elements: 1
Number of Storage Elements: 72
Number of Import/Export Element Elements: 18
Number of Data Transfer Elements: 13
Transport Geometry Descriptor Page: Yes
Invertable: No
Device Configuration Page: Yes
Can Transfer: Yes