I get that on plain ole ADSL.
Currently battling with horrible line noise; have rewired my house completely (it was a spiderweb of shitty wiring beforehand). Essentially I did what this guy recommends:
http://www.geekzone.co.nz/sbiddle/8357
Solved the problem temporarily. Went from 4-6dB SNR and frequent disconnections to 8-9, then all of a sudden lost connection for a few days. Chorus came out and diagnosed some shitty connections external to the house and re-did them, got me back online, but have suffered disconnections since.
Strangely, I updated windows last night and haven't been d/c'd once. Although still only getting a 5.0db SNR margin.
I reckon the process of laying fibre in my street is fucking with my copper. But i'll suffer the inconvenience if it means fibre is coming in a few months.
TLDR - I have unstable net, and can't wait for fibre.