With all the software upgrades has Samasung resolved the issue of having the PBX supervise activity on analogues/fct trunks and disconnect as soon as there is no communications

no changes like all system how can you tell? the only way to tell is when the carrier send you clearing, in which case the busy tone disconnect works on the samsung? better then most other systems.

In uk we get the phone carrier to make off hook select to 800ms

seems to cure the problem best way is to get digital lines

my carrier sends dial tone but still the call is held till the lapse of the set CO-CO duration.