This is my scenario: - New 3CX installation on XP Pro64. - UK PSTN standard phone line connected to SPA3102 which is registered with 3CX. - 2x SPA303 IP phones registered with 3CX. - Calls can be made (internal, outgoing and incoming). This is my problem: if I accept incoming call on my extension, then when I hang up the IP phone, the caller's phone is not disconnected, they hear silence but the call continues. If I plug in analog phone to the PSTN line, I can resume the call. For an outgoing call made from my IP phone extension to the same mobile phone number, hanging up the IP phone does disconnect the call properly, so it seems to depend on which direction the call is going. Disconnect tone on PSTN tab of 3102 is set to 400@-30,400@-30; 2(3/0/1+2) which should I believe be correct for UK, and I'm thinking it must be okay as an outgoing call terminates okay when I hang up. After hanging up the incoming call, the Info tab on the 3102 shows Hook state=On, Voip and PSTN state=Idle, and last PSTN Disconnect Reason as 'Voip Call Ended'. I've tried various settings on the PSTN Disconnect Detection but no change. I would like to crack this problem before I proceed with deployment around the company, don't want to end up with lots of 'stuck' phone calls! David.