I upgraded both my XOs to the new Build 767 then I upgraded Ubuntu from the Gutsy 7.10 version to Intrepid 8.10 see:
Ubuntu 8.10 (Intrepid) for XO - OLPC News Forum
This above install is especially for the XO. It now has much simpler interface.
While reinstalling all my applications (Wine, SeaClear, etc) I discovered that Capn Voyager no longer worked. Found it was missing a couple of DLLs that I guess I had installed in Wine on the old Gutsy version. You need to copy over from your PCs Windows/system32: msvbvm60.dll and ddeml.dll to the ~/.wine/drive_c/windows/system32
I got one of those new 1 Terabyte external hard drives and found it didn't work on either version of Ubuntu until installed the ntfs-3g interface:
sudo apt-get install ntfs-3g