restore CT and KVM failed on PVE2.2

Hello,
I was working with proxmox 1.8 until now and backup/restore was well working with openVZ and KVM.

I installed a PVE 2.2 on a new harddisk and tried to restore all my VMs and it failed.

More details: on my PVE 1.8, Var/lib/vz was pointed through a simlink on /mnt/VM-PROD which is a raid 5 partition in ext2

Now, as i could not create this simlink in PVE2.2, i create another storage pointing directly to /mnt/VM-PROD.

I don't understand , i can not neither create a CT in this storage (named VM-PROD) neither restore all my VM in it .

It fails with message like

TASK ERROR: can't lock container 100

Is there an issue for this migration ?

regards,
stephane