Dynex DX-M100 Modem not working

I borrowed Dynex 56K Data/Fax/Voice Modem (Model DX-M100)and install it . and it is working fine - I can access the internet and use the fax services . It's supposed to have a feature called "Modem on Hold" that allows me to take brief telephone calls without logging off the internet, but it's not working that way. I tried calling myself (using my cell phone) and got the usual busy signal. The documentation that came with the modem and the CD don't address this issue (or any troubleshooting issue for that matter). Does anyone else have this modem installed and know what's wrong? I have Windows XP on my computer.

When you place your Internet connection on hold to take an incoming or make an outgoing voice call, the modem flashes the line, and then remains off-hook and silent. You can then pick up a phone connected to a live jack. When you're done with the call, you hang-up the phone, and select the Resume Internet Connection option on your MoH window.

Important: Many modems are designed so that the "Phone" jack on the modem is disconnected from the line when the modem is off-hook. If this is the case with your modem, you need to use a phone connected to a live jack - the phone cannot be connected to the 'Phone' or 'Tel' jack of the modem, but you can use a splitter and connect both the phone and line cord to the modem's 'Line' jack.

You can test whether your modem's 'Phone' jack is live when the modem is off-hook by connecting a phone to the 'Phone' jack, and picking it up while you are connected to your ISP. If you hear any modem sounds, the jack is live and you can use a phone connected to the 'Phone' jack.

Avoid putting the modem into a 3-way call: Your MoH software may allow you to place your Internet connection on hold and place a voice call. (The 'call for Pizza function'.) When you activate this option, the modem flashes the line, and if you have 3-way calling, you'll have a dial-tone when you pick up a phone. When you're finished with the voice call, it's important that you and the other end hang up before resuming your Internet connection: otherwise, the flash produces a 3-way call with the distant end tied in to your modem->ISP connection.

Modem-on-Hold is a function of the V.92 modem standard and allows telephones on the same phone line to receive an incoming telephone call and stay connected to the Internet. A voice call can also be made while connected to the internet without losing the modem connection. For more information about Modem-on-Hold, go to the v 92 Industry Standard Web site (in English).

Modem on Hold will not function without the following requirements

• Call Waiting must be enabled by the telephone company.
• The Internet Service Provider (ISP) must offer compatibility with the Modem on Hold feature.
• The Internet connection must be made with a v92 compliant modem. This includes the modem driver. If you meet the requirements in this section and still cannot use the Modem-on-Hold feature, try downloading and installing the latest modem driver from HP. For more information, refer to the HP support document Obtaining Software and Drivers .