I have a dedicated W7 Enterprise (32bit) home server that I use for file serving and backup, and it also runs the 3CX PBX with Skype Gateway.
I usually let the server update itself with MS security updates, and quite a few have been installed in the past few months. Unfortunately I don't recall exactly when things stopped working with Skype, so I can't associate it with a Windows update. As far as I can tell there have not been any hardware driver updates in the past few months.
The Skype client itself works just fine on the server. I use a Skype client on my laptop as well, and if I change my online status on my laptop, the Skype client on the server nicely changes to that same status a few seconds later. The tracelog of the Skype Gateway shows a warning that seems to be related to my problem, but I have no idea how to resolve it. Here is the tracelog (I removed my Skype user ID):
22:36:16:279 - Info : Logger started
-------------------------------------------------------------------------
22:36:16:279 - Info : All channels synchronization initialized
22:36:16:279 - Info : This channel synchronization initialized
22:36:16:290 - Warning : Channel started in OPERATIONAL mode
22:36:16:385 - Info : Skype support started
22:36:16:389 - Info : Loading channel settings from C:\ProgramData\_3CXSkypeGateway\3CXSkypeGateway.ini
22:36:16:403 - Info : Attempting to load settings for account 3cxskypeacc01
22:36:16:406 - Info : - network card: [localhost]
22:36:16:407 - Info : - PBX address: [localhost]
22:36:16:407 - Info : - PBX port: [5060]
22:36:16:407 - Info : - RTP range: [22500]-[23000]
22:36:16:407 - Info : - codecs: [PCMU;PCMA;GSM;]
22:36:16:407 - Info : - registration interval: [10] min
22:36:16:407 - Info : - registration retry: [10] min
22:36:16:407 - Info : - SIP transport: [0]
22:36:16:407 - Info : - RTP mode: [0]
22:36:16:407 - Info : - monitor port: [5544]
22:36:16:407 - Info : - service port: [5545]
22:36:16:408 - Info : - master port: [5546]
22:36:16:408 - Info : - master channel: [-1]
22:36:16:408 - Info : Settings loaded OK
22:36:16:408 - Warning : ----------- Logging is now filtered according to option "info warning error time" -----------
22:36:16:472 - Info : Specified network card OK, set to 127.0.0.1
22:36:16:474 - Info : Port check - Port [127.0.0.1:6060] is free
22:36:16:475 - Warning : RTP last port should be odd, fixed to [23001]
22:36:16:475 - Info : RTP port range set to [22500-23001]
22:36:16:476 - Info : PBX server [127.0.0.1:5060] is reachable
22:36:16:480 - Info : Port check - Port [127.0.0.1:22500] is free
22:36:16:897 - Info : RTP engine started OK
22:36:16:897 - Info : SIP: Channel has been asked if allow secure, returning [false]
22:36:16:919 - Info : SIP engine started OK
22:36:16:919 - Info : Starting channel:
22:36:16:919 - Info : - master channel: [no]
22:36:16:919 - Info : - monitor port: [5544]
22:36:16:919 - Info : - service port: [5545]
22:36:16:919 - Info : - master port: [5546]
22:36:16:919 - Info : - expected Skype user: [**My Skype ID**]
22:36:16:921 - Info : Attempting to listen for Skype events
22:36:16:923 - Info : Sending registration request to PBX:
22:36:16:923 - Info : - display name: [3CX Gateway for Skype]
22:36:16:923 - Info : - user agent: [3CXSkypeGateway 2.0.9919.0]
22:36:16:923 - Info : - user: [10000]
22:36:16:923 - Info : - auth.ID: [10000]
22:36:16:923 - Info : - auth.pass: [1234]
22:36:16:923 - Info : - domain: [127.0.0.1:5060]
22:36:16:923 - Info : - proxy: [127.0.0.1:5060]
22:36:16:923 - Info : - transport: [0]
22:36:18:357 - Info : Synchronization thread is running
22:36:18:494 - Info : Skype client attached, now waiting for Skype events
22:36:18:782 - Info : Registration to PBX succeeded
22:36:26:724 - Info : Processing Skype attach request
22:36:26:974 - Info : Skype attach succeeded
22:36:26:974 - Warning : >>>>>>>>>>>>>>> AttachementStatus [4] - overtimed operation with 2358 msec
22:36:26:976 - Info : Waiting for Skype authorization
22:36:56:993 - Warning : Skype connection status is OFFLINE
22:36:57:035 - Info : Expected Skype user logged in: [** My Skype ID **]
22:36:57:051 - Warning : Skype user status is OFFLINE
22:36:57:065 - Info : Skype authorization request succeeded