Make sure to save your settings from the GUI in Maint. > Misc. and take all 4 options.
Then burn ISO onto CD then boot and run the Software installer after POST.

Link below provides details on this video though it shows with USB Flash Stick it will work the same w/ CDROM.

http://www.open-e.com/library/webcasts-and-videos/
2010.09 Installing Open-E DSS V6

It could be that you are on build 4622 and you might try to use the 4786 before going to 5087 or there could be something on volume causing it not to update, try creating a small NAS vol. then run the repair file system from the Extended tools from the Console Screen.