Layers and Multitech V.32/v.42 modems

[eric.a.olson]

    I have AT&T 620 and 730 terminals connected to
    Multitech Multimodem v.32 modems (also capable of
    v.42).  I cannot get these to run layers (xt) on our
    system V R 3.2.2/3.2.3 386's.
    I've got them communicating at 9600 baud,
    set for xon/xoff on the terminal end, RTS/CTS on the computer end,
    and connected to device nodes which supposedly support hardware flow
    control;  I can get into layers, but can't create more than one
    layer without locking up.  Does anyone know or can they suggest
    the proper settings for flow control, etc. to get layers to work?