randy, in the other thread, i learned how to attach pics in a post to a thread, but not a PM:
user cp/settings and options/edit options/miscellaneous options/message editor interface
and change to Full CKE.
this will give you a button to manage attachments after you 'go advanced' when posting a message.
that explains attaching a file to a post in a thread, but i don't know how to do it in a PM.