Problems with net/net-snmp on 5.2-RELEASE?

I'm having troubles getting net/net-snmp working on 5.2-RELEASE -- I've
tried both 5.1 and 5.0.9, and both are exhibiting the same behaviour.  This
is with 5.0.9 (communities changed to protect the innocent):

    newhost# snmpd -d -D -f -L
    newhost# 
    Sending 45 bytes to 10.10.10.2
    0000: 30 2B 02 01  00 04 06 70  75 62 6C 69  63 A4 1E 06 0+.....public...
    0016: 0B 2B 06 01  04 01 BF 08  03 02 81 7F  40 04 40 07 .+.........._at_._at_.
    0032: 99 1B 02 01  00 02 01 00  43 01 04 30  00          ........C..0.

    NET-SNMP version 5.0.9

    Received 64 bytes from 10.10.11.2
    0000: 30 3E 02 01  00 04 07 70  75 62 6C 69  63 20 A0 30 0>.....public..0
    0016: 02 04 82 C7  18 D1 02 01  00 02 01 00  30 22 30 0F ............0"0.
    0032: 06 0B 2B 06  01 04 01 8F  65 0A 01 05  01 05 00 30 ..+.....e......0
    0048: 0F 06 0B 2B  06 01 04 01  8F 65 0A 01  05 02 05 00 ...+.....e......


    newhost#

The debugging output of 5.1 is much, much more verbose, but still exhibits
the same quit-without-error-nor-coredump behaviour.  The querying host
doesn't ever get any response.

(Flag order seems to be important -- this one actually /did/ fork from the
shell.)

And a similar run from 5.1:

    newhost# snmpd -d -DALL -Lo -f

    <snip very verbose debugging>

    dumph_send: SNMPv1 Message

    Sending 46 bytes to 10.10.10.2
    0000: 30 2C 02 01  00 04 06 70  75 62 6C 69  63 A4 1F 06 0,.....public...
    0016: 0B 2B 06 01  04 01 BF 08  03 02 81 7F  40 04 00 00 .+.........._at_...
    0032: 00 00 02 01  00 02 01 00  43 02 00 96  30 00        ........C...0.

    trace: netsnmp_udp_send(): snmpUDPDomain.c, 150:
    netsnmp_udp: send 46 bytes from 0x80e87d2 to 10.10.10.2 on fd 11
    trace: snmp_call_callbacks(): callback.c, 131:
    callback: END calling callbacks for maj=1 min=6 (1 called)
    trace: snmp_call_callbacks(): callback.c, 111:
    callback: START calling callbacks for maj=1 min=7
    trace: snmp_call_callbacks(): callback.c, 119:
    callback: calling a callback for maj=1 min=7
    trace: send_notifications(): notification/snmpNotifyTable.c, 95:
    send_notifications: starting: pdu=805a900, vars=80e7000
    trace: get_target_sessions(): target/target.c, 32:
    target_sessions: looking for: internal0
    trace: get_target_sessions(): target/target.c, 36:
    target_sessions:  for: 0=internal0
    trace: get_target_sessions(): target/target.c, 75:
    target_sessions: found one: internal0
    trace: snmp_call_callbacks(): callback.c, 131:
    callback: END calling callbacks for maj=1 min=7 (1 called)
    NET-SNMP version 5.1
    trace: main(): snmpd.c, 963:
    snmpd/main: We're up.  Starting to process data.
    trace: snmp_sess_select_info(): snmp_api.c, 5570:
    sess_select: for all sessions: 12 11 8 6 
    trace: receive(): snmpd.c, 1100:
    snmpd/select: select( numfds=13, ..., tvp=0x0)
    trace: receive(): snmpd.c, 1102:
    snmpd/select: returned, count = 1
    trace: netsnmp_udp_recv(): snmpUDPDomain.c, 117:
    netsnmp_udp: recvfrom fd 12 got 64 bytes (from 10.10.11.2)
    trace: _sess_process_packet(): snmp_api.c, 4840:
    sess_process_packet: session 0x813e0f0 fd 12 pkt 0x8143000 length 64

    Received 64 bytes from 10.10.11.2
    0000: 30 3E 02 01  00 04 07 70  75 62 6C 69  63 20 A0 30 0>.....public..0
    0016: 02 04 1A F2  D6 02 02 01  00 02 01 00  30 22 30 0F ............0"0.
    0032: 06 0B 2B 06  01 04 01 8F  65 0A 01 05  01 05 00 30 ..+.....e......0
    0048: 0F 06 0B 2B  06 01 04 01  8F 65 0A 01  05 02 05 00 ...+.....e......

    newhost#

Any pointers or suggestions?