Having posted the email below - I spent time verifying all the servers
through web access and realized that although the IMAP server did not
have SSL enabled, the Dav access did. Once I had them both set to SSL,
magically all my missing calendar data appeared!!
I think (fingers crossed) it now works correctly.
Having calmed down from my frustration with this - I must say I
believe Microsoft should do a far better job of providing diagnostics
and error reporting for this software. The fact it silently fails when
synching with no error messages, and also behaves oddly when
installing (see the comments below re the contact/calendar folders)
should not happen.
Exchange is their product and they ought to be able to provide an
easier installation process - even if they refuse to properly
implement MAPI.
Thanks again to the patient people who helped.
