That means your line is unstable for some reason at the provisioned speed, and ADSL is dropping the sync rate as a result. You'll want to investigate if you are having line troubles that is causing excessive noise, or if your line is simply too long to reliably hold the speed for an extended duration of time.
To start, the Transceiver Statistics are a good place to check first. Please supply the stats to us, and if you need help getting them, just tell us the make and model of your modem. In most cases we're able to get them without needing Verizon's help.
#1 When you look for the Transceiver Statistics, this text gives to you an idea of what to look for:
Line Mode, Data Path:, Transceiver Information Down Stream Path Up Stream Path, DSL Speed (Kbits/Sec), Margin (dB), Line Attenuation (dB), and Transmit Power (dBm).
#2 As where the Transceiver Statistics are located in the DLink 2750:
To my knowledge, no one has managed to find and report the location of the Transceiver Statistics page on the D-Liink mode, so we'll need Verizon to grab the stats from the DSLAM, and while they're at it, check the logs on their end to see if the line is dropping out physucally, or is dropping out on another sense.
In that case, I would suggest eitther:
a) getting one.
Regardless if that new dsl modem is from Verizon or you get your own, as long as it not a D-Link DSL-2750B.
b) OR borrowing a neighbor's dsl modem, as long as it not a D-Link DSL-2750B.
I have to same problem with my 2750 but I have an Actiontec GT784WN coming on Wednesday to try a different modem/router.
I wasn't having a problem with this until my Westell died and Verizon sent me the D Link 2750.
We'll see on Wednesday.
I'm having to reboot at least twice a day to re connect.