[TenTec] QSK/QRQ problem with Orion / ACOM 2000A

[NJ0IP]

One of our local hams is having problems mating his Orion 564 to
his ACOM 2000A (automatic linear).
The problem is only when trying to run full QSK at speeds above
40 wpm.
In SSB or when running slower speeds, everything works just fine.

First he tried to use the QSK keying loop, but found at high
speeds, the characters were being shortened to the extent that
the code was not readable.

The next step was to key the amp in the normal fashion, as if it
were not a QSK amp.
He adjusted the keying delay to give the amp time to switch its
TR relay.

The problem when running this way is, the 2000A gives an error
message: "ARC Fault", which I believe indicates a bad SWR between
the TX and the AMP.  Sounds to me like the amp's relay isn't
switching fast enough.

This problem only occurs when a dit is keyed.
If he keys a dah, there is not problem.

Has anyone used the ACOM 2000A with the Orion successfully under
these conditions, or, does anyone have any suggestions of how he
might successfully use the two together for high-speed CW?

Tnx es 73
Rick