Why is vi acting up suddenly?

[Alexis Rosen]

A few months ago vi suddenly started doing something rather unpleasant. This
change didn't seem to correspond to any alteration I made to the system. I
had hoped that it would vanish when I upgraded to 2.0.1 but it hasn't, so
here is the problem:

vi will no longer work with job control. Suspending it with ^Z works fine,
but when I resume it with "fg" it scrolls the screen up 24 lines or so and
says:
Don't know enough about your terminal to use stop
[Hit return to continue]

Now that's the kind of message I'd expect to see if TERM wasn't in the
environment, or was incorrect. But it's fine, as is proven by the fact that
I can do :q to quit, and then start up vi again, at which point it works
fine. Even stranger, I can do a ":sh" from vi, and when I return to vi from
the subshell, it works fine.

Does anyone have any idea what the problem is?

TIA,
---
Alexis Rosen
Owner/Sysadmin, PANIX Public Access Unix, NY
{cmcl2,apple}!panix!alexis