There are two drivers (mmx and non-mmx) available.
So for example:
C:\IT> it /sITEWSCOD.DRV
Also make sure you have loaded EMM386 correctly.
DEVICE=C:\DOS\EMM386.EXE RAM H=255
I you're running Win98 or if you're using an EMS board you don't need EMM386.
That "files scroll normally when played but no sound" issue is something I've seen myself.
I had an old onboard-SB16 with that problem. I've fixed it my manually setting up
those IT drivers (it /sITSB16B.DRV A220 I7 D1 or something like that).
Another problem was that i was using EMM286 on my 386 (I didn't want EMM386 on that).
But apparently IT makes use of DMA so it didn't work.
This was probably not very helpful, but I'm afraid that's all I can say.