Erm, if you do the changing of the first line in the Updater XML to true, then you shouldn't be having problems running the updater, which in turn will perform the OpenAL32.dll download....
I had edited the the XML file, but on running the updater I was getting errors reporting a missing dll. I downloaded the dll from a link provided elsewhere in this thread which on copying to the installation folder resulted in errors involving a corrupt zip file and reports of "can't delete /thing/updaterinfo.xml.bak!" (or something similar). Using the dll from the link I posted solved the problem.
