diff -upNr qpxtool-0.6.1.orign/lib/include/qpx_transport.h qpxtool-0.6.1/lib/include/qpx_transport.h
--- qpxtool-0.6.1.orign/lib/include/qpx_transport.h	2007-08-19 16:04:14.000000000 +0200
+++ qpxtool-0.6.1/lib/include/qpx_transport.h	2008-02-16 23:00:32.000000000 +0100
@@ -78,6 +78,14 @@ class autofree {
 
 #if defined(__linux)
 
+const unsigned char scsi_command_size[8] =
+{
+	6, 10, 10, 12,
+	16, 12, 10, 10
+};
+
+#define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
+
 //#include <sys/ioctl.h>
 #include <linux/cdrom.h>
 //#include <mntent.h>
@@ -159,7 +167,7 @@ public:
 	    }
 #endif
 	}
-	sg_io.cmd_len = i+1;
+	sg_io.cmd_len = COMMAND_SIZE(cgc.cmd[i]);
 	return cgc.cmd[i];
     }
     unsigned char &operator()(size_t i)	{ return _sense.u[i]; }
diff -upNr qpxtool-0.6.1.orign/lib/qpxtransport/include/qpx_transport.h qpxtool-0.6.1/lib/qpxtransport/include/qpx_transport.h
--- qpxtool-0.6.1.orign/lib/qpxtransport/include/qpx_transport.h	2007-08-19 16:04:14.000000000 +0200
+++ qpxtool-0.6.1/lib/qpxtransport/include/qpx_transport.h	2008-02-16 23:00:32.000000000 +0100
@@ -78,6 +78,14 @@ class autofree {
 
 #if defined(__linux)
 
+const unsigned char scsi_command_size[8] =
+{
+	6, 10, 10, 12,
+	16, 12, 10, 10
+};
+
+#define COMMAND_SIZE(opcode) scsi_command_size[((opcode) >> 5) & 7]
+
 //#include <sys/ioctl.h>
 #include <linux/cdrom.h>
 //#include <mntent.h>
@@ -159,7 +167,7 @@ public:
 	    }
 #endif
 	}
-	sg_io.cmd_len = i+1;
+	sg_io.cmd_len = COMMAND_SIZE(cgc.cmd[0]);
 	return cgc.cmd[i];
     }
     unsigned char &operator()(size_t i)	{ return _sense.u[i]; }