ovftool fail with error message "Disk Transfer Failed\n Error: IO error"

I'm trying to deploy one ovf file to my ESX 4.0

ovftool -v

VMware ovftool 1.0.0 (build-166674)

following is my command line.

ovftool --powerOffTarget --powerOn --overwrite=true --datastore=storage1 --name=base1 /NSN/Virtual_Machines/BASE/latest/Base.ovf vi://Administrator:pass@10.32.230.100/project/host/projectbld/

the result is:

Opening OVF source: /NSN/Virtual_Machines/BASE/latest/Base.ovf

Opening VI target: vi://Administrator@10.32.230.100/project/host/projectbld/

Target: vi://10.32.230.100/project/host/projectbld/

Disk Transfer Failed           

Error: IO error

I can see base1 directory generated on ESX projectbld on storage1 , and some zero size are created , too

and I can also see  "Deploy OVF template" on my vSphere Client.

but the progress on vSphere Client will be the task was canceled by a user.

and ovftool fail.

who can tell me what's going wrong? or where is the log to investgate on both ESX and ovftool host?