To VirtualDubDevelopers. please, please help me!!

Please, please, help me. We are just about to release a free codec for compressing surround sound (it will have 128 kbps and sound far better than mp3surround and it will be FREE).
Now we try to test our ACM codec, to be used with VDM. But I have a problem with the VirtualDubMod (1.5.10.1). I am not able to compress 6 channel audio files. I have also tried to use ACM AC3 codec (on external 6chn PCM stream), but the resulting file has 0 kb. The same story is with my codec. I am obtaining 6 channel PCM, decoded with the AC3 ACM codec, but the compression in VDM does not work.
During debuggin I have noticed that in the first attempt to compress (ACM stream convert), flag indicating the audio stream says that it is the end of the stream.
Maybe the reaseon is that the stream frame size should be dividable by 4? (for 6 channel stream it is not). So maybe the VDM treats it as the last, incomplete frame, and based on this guesses that this is the end of the stream?
:-(
Please help me with this (guy who is coding the ACM codec has only one week to work on it. If he does not, then we will not be able to provide the ACM encoder for our codec).