Internal resistors activated or not, it would be cheap and especially quick to put a couple of resistors on A4 & A5. The issue ("my wii nunchuck data becomes corrupt") sounds like logic levels floating too erratically to hold a "clean and consistent data stream", and the solution if thats the problem, is a couple of pull ups.
I've read of people using 1.8, 4.7 and 10k on a wide range of different devices, so if you've got them handy you've got nothing to lose by trying.