I have the same issues.. 20 machines work fine, 2 or 3 don't. I can reinstall and they will work for a few weeks, then suddenly stop. Uninstall/Reboot/Re-install and the line selection is not available. Sometimes it will just pop-up as a selection for no apparent reason. The client shows connected and initialized. Can ping the published IP just fine. XP sp1, Office XP, BCM 3.6. All the PCs are identical and connected the exact same way. I have been fighting this for months. No firewall between the PC and the BCM, windows firewall is OFF.
Shows In Service TSP 6.6.1.60.A.0 Switch Type T1 GLB 3.6 CTI Device CTI. Client is set in the BCM, 16 Licenses, 12 show In-Service.
Tried the Personal Call Manager. The Line does not show up in there as a availble selection either.