The reason my first message is so ambiguous is because by doing the same thing the last two times has prompted a mod to contact me and sort the problem without a 2hr phone call to a far away land.
I was told that the cabling would be different between the bb and Infinity services and that it would sort the problem. Clearly not exactly true.
Whenever the engineers come they confirm nothing is wrong inside the house and say they are off to check elsewhere...then I never hear anything back. According to my phone call last night, they only have access to my records since being on Infinity. Which is very convenient and very strange. They acknowledge that there is a problem, but can't tell me what it is.