Digital Line Detected after Support Upgrade

Dell Support every now and then sends a popup on my machine to clean up desktop icons or see if I have the latest Windows patches etc. They upgraded the process recently and so I updated it on my machine a few days ago. Since then, every now and then I get a "Digital Line Detected (PBX)" message. It asks me to verify that my phone line is connected to a standard analog modem or fax line. I have DSL. There is no phone line connected to anything except my DSL modem. When I get this message I get a "thunk" sound just prior to the message. I suppose Dell support is trying to get hold of me and gets thunked by my computer. Any idea on how to rid myself of this message?