after spruceup imports both the .m2v and the .ac3 files. I get an error saying that the bitrate was inconsistent in the .ac3 file. I burned it to dvd-rw and the picture was perfect, but it had no sound. I've tried it twice and got the same results. Can anybody help?

Pretty sure it is because your have a VBR AC3 stream and Spruceup doesn't support VBR AC3's. Either transcode to a CBR AC3 or use another authoring package that does support VBR.