If you have both Foxtel pay TV and Bigpond cable Internet, then it's possible you're not getting optimum TV quality. A staff member at Lifehacker publisher Allure Media was suffering bad picture quality on his IQ2 box and contacted Foxtel customer support, which immediately said that the problem was probably caused by interference on the line, and sent out a free filter to fix the issue. Lifehacker contacted Foxtel, which confirmed that the solution is available, though it says the problem isn't common:
If a cable subscriber who has Bigpond and Foxtel experiences issues with audio or video quality a filter can be supplied by Foxtel, but this is not a widespread issue from our customers.
If you are suffering from visual or sound problems, though, seems like a phone call might be in order. Thanks Ben!