Trouble Downloading to External LMS

Hi everyone.  I have 3 modules created and published (Presenter '09) in exactly the same way (published in SCORM 2004).  Two of the 3 courses download and function perfectly on the external LMS (Litmos).  The 3rd will not download.

I split that module into 5 parts, hoping to isolate the problem.  All 5 downloaded and played perfectly on Litmos. 

I reconstituted the module from the 5 pieces ( re-did branching, hyperlinks  etc.), and it again won't download.  The administrator of the organisation for which I have created the modules says the error message at Litmos is that, "...it is a bad file."

I have no idea what to do next to try to figure out what the problem is with downloading this module?  I would really appreciate any suggestions.

Thanks.

Judy