But the problem is, im only using 12 staves with the flutes and bassoons doubled up (I have yet to insert the brass), and the flutes have their own channel to themselves. Bill, i think your second possibility is more likely, because the whole movement is about 16 minutes long and i split that into two files, thus 6 minutes may be too much for the soundcard as well.
On my windows 7, when i do fairly large works (for example, right now im copying the second movement to beethovens ninth) some notes that are sustained for a few measures will only make a small stacatto sound or sometimes no sound at all. For example: in the 2nd movement to beethovens 9th, at the first few bars of letter H, the sustained note that the first flute is supposed to play is cut terribly short when i play the whole thing through or start from several bars before letter H. please help!