--- src/sys/dev/disk/ata/atapi-cd.c	2006/12/22 23:26:15	1.28
+++ src/sys/dev/disk/ata/atapi-cd.c	2007/05/09 00:53:32	1.29
@@ -1157,7 +1157,7 @@ acd_start(struct ata_device *atadev)
 
     bzero(ccb, sizeof(ccb));
 
-    track = (dev->si_udev & 0x00ff0000) >> 16;
+    track = (dev->si_uminor & 0x00ff0000) >> 16;
 
     if (track) {
 	blocksize = (cdp->toc.tab[track - 1].control & 4) ? 2048 : 2352;