The path_info_disabled mode doesn't cause OAI to break entirely, but it does cause OAI to operate in a way that's slightly outside of the OAI specification. Some OAI tools will like this, others won't. Basically, it's because path_info_disabled makes use of request parameters instead of the PATH_INFO CGI variable in order to work around servers that don't support PATH_INFO. However, the OAI spec says that request parameters beyond the ones used by OAI itself are not allowed.
The path_info_disabled mode is not recommended -- not least because the URLs it produces are unwieldy. Generally it's only provided for users with low-end shared hosting. If you do have a chance to lean on your system administrator, getting it working shouldn't be much work.
Meanwhile, if you're interested in the XML transformation tool, it's currently in testing. Lean on Alex Garnett (see https://pkp.sfu.ca/about/people/
) for more information.
Public Knowledge Project Team