I have posted before for help on this topic and nothing worked to give me Caller ID notification in WMC7 on my X64 system. I tried YAC including the Babgvant mods, Vista CallerID, TapiRex etc.. Despite repeated tries, registry tweaks etc. Nada. The Caller ID servers always worked in windows but never in WMC even though the addin/pluggin was installed, registered and visible in Extras, the notification poppups never worked in WMC.
But a new Caller ID package W7CallerID and their WMC plugin was recently released and it works! Finally! The last thing off the list to get WAF on the HTPC. With this and the new HDHR Prime firmware. WAF achieved at least for the HTPC. Goodbye Verizon boxes! Although I have yet to try on the Xboxes
W7CallerID is free trial and there is no indication what it might cost later....?