> > does anyone have any clue what this is?

> No, not really unless you give us more specific information.  Like
> what programs you were running at the moment, etc.

i've seen it in xterms, emacs, and lyx.  in xterms, it selects the text;
in emacs it goes up a few lines (which would happen with the mouse
selection, given emacs interface), and in lyx it selects the text (with
catastrophic results).

> However, it sounds like either your Mac or your ADB devices are acting
> up...  Does it still happen even if you disconnect the Kensington?

I haven't tried it without the kensighton, although that device seems
unlikely-- i've never had an extraneous cursor move under macos.  The
edge of my right hand seems to touch keys even at rest, though--this is
where my suspicions are centered.  With a base X installation, is ther a
way to block-select from the keyboard?

rick