Dynamic LUN Resize not working

Dynamic LUN resizing worked one time initially when setting up the environment. Now when you hit rescan in Xencenter it acts like it does something, but the size does not change. SMlog (attached) mentions the following:

sr_scan {'sr_uuid': 'df10459a-dbf8-e7a0-e4ea-ff90556fb920', 'subtask_of': 'DummyRef:|eb5b54d7-4364-827a-7545-f963bf92fed3|SR.scan', 'args': ], 'host_ref': 'OpaqueRef:41dd3dc7-1545-40f5-d480-e2d15a2f068a', 'session_ref': 'OpaqueRef:1e16c5ef-c098-0640-9862-038feb90a604', 'device_config':

{'device': '/dev/disk/mpInuse/000b08002d002506', 'SCSIid': '2000b08002d002506', 'SRmaster': 'true'}

, 'command': 'sr_scan', 'sr_ref': 'OpaqueRef:e9664668-9630-ffaa-475e-eedb04a4d4d1'}
Jan 23 18:49:50 knx-xen11 SM: [2221] LVHDSR.scan for df10459a-dbf8-e7a0-e4ea-ff90556fb920
Jan 23 18:49:50 knx-xen11 SM: [2221] ***** Error in scsiutil.refresh_lun_size_by_SCSIid(2000b08002d002506): EXCEPTION exceptions.ValueError, too many values to unpack
Jan 23 18:49:50 knx-xen11 SM: [2221] File "/opt/xensource/sm/scsiutil.py", line 557, in refresh_lun_size_by_SCSIid
Jan 23 18:49:50 knx-xen11 SM: [2221] currentcapacity = sg_readcap(primarydevice)
Jan 23 18:49:50 knx-xen11 SM: [2221] File "/opt/xensource/sm/scsiutil.py", line 653, in sg_readcap
Jan 23 18:49:50 knx-xen11 SM: [2221] (blockcount,blocksize) = stdout.split()