#27 Simple Ack failure

[bob zamojcin]

There is a problem with recognition of a simple ACK
reply to a confirmed Alarm/cov notification. The
acknowledge message appears on the LAn, but VTS fails
to recognize it. This problem first appeared in VTS
2.27, but was not apparent in VTS 2.24.

Again, this problem does not impact immediate testing,
but will affect the next round of testing.