I have a number (dozen or so) GoDaddy installs.  ZERO have been successful using their upgrade process.  ALL (4 so far) have been successful out of the gate using Chris Hammond's upgrade path/post, repeated here.  [I take no credit.  It just works]  I always get the backup site working first, then do production while 'pointing' to the backup over night.  ::

Chris says...

Upgrade using App_offline.htm to disable WebSite


1) Download the DotNetNuke_Community_XX.XX.XX.UPGRADE.zip package of the latest stable release of DotNetNuke.


2) Right-click on the icon of the downloaded package, select "Properties" from the context menu, click on the "Unblock" button. Due to MS Windows security, certain files (.vb, etc.) will not extract properly without performing this step.


3) Extract the contents of the UPGRADE package into a folder on your computer, it is not recommended that you extract directly over your website yet.


4) Backup your website files


5) Backup your database


6) Make sure you completed steps 4 and 5


7) Add an app_offline.htm file to your website's root directory, this will disable the application from responding.


8) Did you backup your website and database as mentioned in steps 4 and 5? If not, be sure to do that.


9) Copy the files from the extracted UPGRADE package over the contents of your website's folder.


10) Open your web.config and make sure autoupgrade is set to FALSE not TRUE


11) Rename the app_offline.htm file to app_offline.htm.save


12) Access your website by browsing to it in a web browser, you will be redirected to an under construction page. 


13) Change the url to http://MYWEBSITE/install/install.aspx?mode=upgrade


I use CKEditor which requires a different DNN6 install, so I put their DNN6 install zip file in the install/module folder before I run step 11...
Bob H.