sounds like you need a better program. if you dont mind spending an extra 7 dollars a month i'd go with callwave. its a good program and shows all calls. and has settings where a blocked number must show their number

 

www.callwave.com

 

You didn't say which modem is installed in your 8400. I have the optional Telephony Modem (D850 Conexant v.9x DFVc modem) and it does not get ANY caller ID information in Type 1 (formatted). Type 2 (unformatted - almost useless) works fine. The modem monitor program checks the modem and it responds to AT+VCID=1 with an "OK" but fails to get any information sent between ring 1 and ring 2 (like DATE = , TIME = , NAME =, ETC.).

After 4 weeks, I received a replacement modem from Dell and guess what? It reacts the same way. No caller ID received after an AT+VCID=1 "OK" response. While amusing Dells techs both in email and voice help with the problem, I ordered another brand (cheap) internal modem and installed it so caller ID is working in all telephony software programs I have. I should receive another replacement D850 Conexant modem from Dell next week and I will report back with the results of that installation.

The 2nd replacement modem arrived, was installed, and tested.  Same problem. The modem (D850 Conexant - refurbished) responds with "OK" when receiving the command AT+VCID=1 (enabling Type 1 Formatted display of caller ID information) and again no caller ID is available. Ordering a "telephony" modem on your new Dell computer is a mistake!  If you are having problems with no caller ID information using Classic Phone Tools (a program installed by Dell) or any 3rd party answering machine programs that relies on caller ID, look elsewhere for a modem.