Endpoint Encryption

I have set up a policy to encrypt email sent to specific domains.  However, when sending out a meeting request, my PGP Desktop 10.1.2 seems to have stripped out the meeting information entirely and sent it onto the recipient as an email only.  I haven't found any other folks complaining about this, so I expect it is something I've done.  Can anyone comment or provide a way to get around this behaviour?

Having seen this on a customers site too, unfortunately he didnt report any further comments on this problem, so you are not alone in this case.