Okay, so the problem seems to have been resolved, and in this case it does seem to be a TDE problem; or at least, a problem with the kopete-trinity package.
I cannot torify Kopete, and the available configurations are obsolete. I got away with not being able to configure within the client by torifying Kopete over a secure shell. But now that doesn't work.
However, for myself the problem is solved by using psi-plus, which seems to work great (so far ... fingers crossed), and has the further advantage of being a cross-platform application, rather that specific to TDE or (for that other version of Kopete) the KDE4+ versions.
I don't know if this qualifies as something to be investigated by the devs, but there it is.
Bill