--- linux-2.6.19-rc5/include/linux/igmp.h	2006-11-16 16:11:53.000000000 -0800
+++ linux-2.6.19-rc5T1/include/linux/igmp.h	2006-11-16 16:15:46.000000000 -0800
@@ -191,7 +191,7 @@ struct ip_mc_list
 #define IGMPV3_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
 #define IGMPV3_EXP(thresh, nbmant, nbexp, value) \
 	((value) < (thresh) ? (value) : \
-        ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant+nbexp))) << \
+        ((IGMPV3_MASK(value, nbmant) | (1<<(nbmant))) << \
          (IGMPV3_MASK((value) >> (nbmant), nbexp) + (nbexp))))
 
 #define IGMPV3_QQIC(value) IGMPV3_EXP(0x80, 4, 3, value)