I hate to follow up on my own message of 1996/03/23, but I finally
remembered where I found the note that cutting and pasting are
problematic under X. From the 'xterm' manual page

BUGS
Large pastes do not work on some systems. This is not a
bug in xterm; it is a bug in the pseudo terminal driver of
those systems. xterm feeds large pastes to the pty only
as fast as the pty will accept data, but some pty drivers
do not return enough information to know if the write has
succeeded.

You can test whether this is what happens to you by simply pasting into
'cat' instead of GAP.

Unfortunately that still doesn't help you of course. But maybe you can
find a fixed version of 'xterm' for your system.

Martin.

-- .- .-. - .. -.  .-.. --- ...- . ...  .- -. -. .. -.- .-
Martin Sch"onert,   Martin.Schoenert@Math.RWTH-Aachen.DE,   +49 241 804551
Lehrstuhl D f"ur Mathematik, Templergraben 64, RWTH, 52056 Aachen, Germany