I don't know if this is related to the well-known problem some people (like me) have of KAD in amuled disconnecting and never connect again, but with the last versions of amuled cvs I've found these lines on the log:
2007-09-06 10:44:04: Connected to Kad (firewalled)
2007-09-06 10:44:04: Connected to Kad (ok)
2007-09-06 12:29:19: Disconnected from Kad
2007-09-06 12:29:19: Indexed.cpp(249): Kademlia Indexing: CInvalidPacket Exception in CIndexed::readFile: CInvalidPacket: Integer tag expected, but found ""=Type=10
2007-09-06 12:29:19: RoutingZone.cpp(150): Read 197 Kad contacts
2007-09-06 13:29:20: Kad started.
These are from last build (CVS 20070906) but it happened the same with the last few september ones I tried (sorry, I didn't updated my amuled in August due to holidays...

)
also, whenever I stop amuled, it saves an empty nodes.dat file of 4 bytes, so I have to get a new one at every restart. This always happened as far as I remember...