HP Switch 3500yl-48G(J8693A) strange MAC disappearance

[lefan]

There are 4 HP Switch 3500yl-48G(J8693A) (K.15.10.0009, ROM K.15.30). All 4 switches connected in mesh network. Two of them connected to router over trunks. STP is enabled and default. Detail in attached file "ProCurve-issues.pg"

Have quite strange behavior.

1. Ping from host2 to hostX - all fine:

[root@localhost ~]# ping 10.128.149.8
PING 10.128.149.8 (10.128.149.8) 56(84) bytes of data.
64 bytes from 10.128.149.8: icmp_seq=1 ttl=64 time=0.542 ms
...

64 bytes from 10.128.149.8: icmp_seq=9 ttl=64 time=0.602 ms
^C
--- 10.128.149.8 ping statistics ---
9 packets transmitted, 9 received, 0% packet loss, time 7999ms
rtt min/avg/max/mdev = 0.541/0.567/0.615/0.038 ms

from switch:

R1SW1# show mac-address vlan 100

Status and Counters - Address Table - VLAN 100

MAC Address Port
------------- -------
001b21-c56ce0 5
001e79-305400 Trk1
002128-453905 9
0026f1-3c6c40 Mesh
0026f1-412e00 Mesh
64d814-dce40e Trk1
64d814-dce40f Trk1
b499ba-8db500 Mesh

The Port 9 belongs to HostX.

2. If I try in same time ping HostX from Host1, the all fail.

MAC address disappear from switch and ping fail fom host2 and host1.

Status and Counters - Address Table - VLAN 100

MAC Address Port
------------- -------
001b21-c56ce0 Trk1
001e79-305400 Trk1
002128-453905 Trk1
0026f1-3c6c40 Mesh
0026f1-412e00 Mesh
64d814-dce40e Trk1
64d814-dce40f Trk1
b499ba-8db500 Mesh

[16again]

MAC address 002128-453905 doesn't disappear, it moved to trk link!  There must be some looping going on.
Double-check bonding and STP on redundant links to the router