Issue moving a raid-1 to larger hdd

Hi, I'm moving a 500gb data only raid volume to a 2tb. I've follow the instruction here Intel� Rapid Storage Technology (Intel� RST) — Move a RAID 1 volume to larger hard drive.

Everything work smoothly up to step 18. There, in the Intel Rapid Storage Technology user interface, When creating the new volume, i'cant select which drive data to keep, the option are greyed out??!?  Any clue??

FYI : win2k3 sp2 (on another raid 1 volume) on an Asus P5Q-E (intel P45/ICH10R). On the 2tb hdd, there are 2 partitions, filling the whole drive.

Thanks for your help.