Resolution Issues running Ubuntu on VirtualBox
Solution 1:
Wes made a comment on the article you mentioned which helped several others that had the same problem:
Wes:
Slight change for step 3 on new version of VirtualBox for Windows Hosts. there are different versions of the additions for x86 and amd64 platforms. between setps 2 and 3 you can type ‘ls’ and see what the exact name of the additions are for your platform, then do “sudo bash ./VBoxAdditions-###.run”, replacing the ### with x86 or amd64.
Try running the sudo bash ./VBoxLinuxAdditions-x86.run
command after cd
-ing to the guest additions installation CD.