Autoland disconnecting

Hi guys, Im having a problem with the autoland. This is the current set up: Both FD's are on.Both ILS frequencies tuned and active and matchingBoth courses for the runway are set and matchingVOR LOC switched on and captured (VOR/LOC green)Both CMD autopilots onPlane under the glideslopeFlaps configured (from FMC APPROACH REF page) at 30degress, and speed correctAutobrakes at 2, and speedbrakes armedGear is down The problem is, the plane catches the slope without problem and starts decent. After about 10 seconds, one of the CMD buttons switch off, so i turn it back on, all good. After a few more seconds (about a 10 seconds give or take) it goes off again, then the auto throttle kicks out as well. Winds arnt particularly strong - 8kt headwind with only about 4kts from the right. Looking at my situtation above, am i missing anything? The rest of the flight is fine...