Seems to have happened, but I'm getting a buzzing noise when the bass hits a particular low register and it's pretty frequent. The problem seems to be with the left speaker. I have, however, been able to nullify it by turning the Dynamic Bass to Middle, Low or Off, just seems to be occurring when it's set to High. Blown speaker perhaps?
What are you listening to? I get a similar problem on some cable channels but not others (32pd5200). If it is happening regardless of input it is the speakers. If not, isolate where it does happen and see if there is a common symptom.