ReadyNas Duo v1 disk upgrade - space expansion not shown

Hi,

One of my disks in my ancient, but trusty ReadyNas Duo v1 (Firmware: RAIDiator 4.1.14 [1.00a043] ) had died and I decided to upgrade the disks to the following:

WD 2TB SATA lll Hard Drive for 24x7 Network Attached Storage

Here's what I did:

0) I created a backup of the data

1) I hot swapped the dead disk for a new disk and the NAS recognised the disk 

2) Started and completeda RAID sync, but here's the firs weird thing:

WDC WD20EFRX-68EUZN0 [1863 GB] - 1394 GB allocated - strange I thought, but I figured the expansion would only take place once the other disk is in place as well

3) hot swapped the second disk, recognised it and started RAID sync

4) RAID sync complete and both disks show up as follows:

Ch 1 : WDC WD20EFRX-68EUZN0 [1863 GB] 1394 GB allocated

Ch 2 : WDC WD20EFRX-68EUZN0 [1863 GB] 1394 GB allocated

I tried following the advice from this post and rebooted the NAS a couple of times, but still no change.

Any idea what I did wrong and if I can fix it?

thanks,

Phil