diff -r 41911d90022d nbd.c
--- a/nbd.c	Fri Dec 14 12:39:25 2007 -0600
+++ b/nbd.c	Fri Mar 14 09:01:46 2008 -0500
@@ -327,7 +327,7 @@ int nbd_trip(BlockDriverState *bs, int c
 		} else {
 			TRACE("Writing to device");
 
-			if (bdrv_write(bs, from / 512, data, len / 512) == -1) {
+			if (bdrv_write(bs, (from + dev_offset) / 512, data, len / 512) == -1) {
 				LOG("writing to file failed");
 				errno = EINVAL;
 				return -1;