Petter and I have been trying to debug this since yesterday afternoon. Unfortunately, its not really apparent where the leak is coming from. We continue to debug..
I certainly can provide the 2.0 DShow encode sample. I confirmed that this filter does not have the same memory leak however, there are some limitations with this sample as well. The 2.0 sample does not have YUY2 input pin support. We added that with 3.0.
We are continuing to look at the problem today, and I hope to have something to say later today.
If you want me to transfer MSDK 2.0 sample to you, please write me directly at: email@example.com to coordinate the transfer.