I just got off the phone with the Acer Tech Support people here in Australia. Not Good news
The drive will lock on a region after 5 region changes, this can be rest only 5 times, ie 5 x 5 =25 region changes. Then your drive si permanently locked onto the last region. No way to reverse, reset or over come the region lock.
So, the other option was to buy a second drive (ie one for region 1, and one for region 4). The Second drive is AU$250 and can be ordered from Acer Parts Center (Aust) under the part number 6M.FR4V7.001
I am very very dissapointed wiht this feature of the Acer. That is three things now that annoy me.
1) Bluetooth Mouse has extremely poor response (especially for gaming)
2) Sensitivity of the Keypad can not be increase enough for mouse speed across screen.
3) DVD region lock after 5 regions changes plus 5 resets.
Everything else I about this notebook I love.