modem on voipo line?

My mom has the Arbitron rating system that dials out each night to report the TV shows she watches (or sleeps through...).

I saw a number of 1 min calls to an 800 number which repeated 4 or 5 times a day. She said Arbitron called to tell her they weren't getting the data, so I'm assuming her ATA doesn't like a 56k modem. Has anyone else experienced something like this?

I removed the device and installed it on her pots / dsl line and it's working again, but that's a limited use line and has a finite # of calls allowed per month before AT+T starts gouging, I mean charging extra.

Not recommended at all.

Even so, check out this thread:
http://www.dslreports.com/forum/remark,23837601

Will not work...

I know Nielsen will pay for a POTS or the tech can connect a cell phone box to the monitoring equipment.

They probably weren't very happy about you disconnecting their equipment. They upload that stuff to use for the next days ratings, big bucks ride on those reports you disconnected from the phone line.

Plus, perhaps a violation of agreement to even discuss membership in a viewer ratings service such as Arbitron, Bridge, Nielsen.