Having the same problem.. either error 319 or 407. Rang last week and was told it would be fixed the day after by 9am. Ringing VM again now, and won't be happy with the 'it will be fixed by 9am tomorrow' answer!
I rang.. service will be fixed by 3pm tomorrow! On the plus side VM will text me when it is fixed. Not sure I believe them though, feeling fobbed off again. I almost changed to Sky in December and I've been with cable since it started as Cable and Wireless so many moons ago, as we the first area to get it.. slipping service levels with VM may tip my decision to move!