3b2s communicating poorly

[0000-Admin0000]

Site sscnj has a 3B2/400 running SV R3.0 and a Telebit TB+ on a PORTS card.

Site mccc has a 3B2/400 running SV R3.1 and a TB+ on a PORTS card (although I
could switch it to an EPORTS card if that would help).

Today, sscnj called mccc three times, to pick up a 30453 byte file thatwas
spooled for it.  Here's what happened.

1)  At 12:10, the file was transferred in 448.96 seconds.  mccc's logs shows
many messages like this:
		BAD READ (expected 'C' got FAIL)
The file was not removed from the spool queue.

2)  At 12:26, sscnj called again.  mccc's logs shows
		CAUGHT (SIGNAL 1)
at 12:31.

3)  At 12:32, sscnj calls again and transfers the file in TWENTY-THREE POINT
EIGHTYFOUR seconds!!

Questions: what can we do to insure reliable communications between sscnj and
mccc, and what on earth is going on?

(mccc has reliable connections to other TB+ sites albeit none with 3B2s.)

Thanks.