Well, I got a second installation of Zope running OK in another directory after correcting some group/permission errors on my part. It seems I can now use FSSession with this second installation with no problems (fingers crossed "Oh please please please"). In my original Zope installation, I'm still getting the same EOFError when I try to view a document containing <dtml-call FSSession>. I have been unable to reproduce the original TransactionError in the original Zope. I have mucked around with the 1st Zope since receiving this initial TransactionError - mostly removing var/Data.fs, etc.. and reinstalling FSSession etc... so that I could start "fresh". If I get the original Zope to behave I'll describe the procedure... Thanks, Brian