HSRP state change

[emilio1973]

I've got two routers: a 2821 with an interface GigabitEthernet (Active) and a 2620 with an interface FastEthernet (Standby) normally performing in a HSRP mode:

interface GigabitEthernet0/1
description LAN XXXX
ip address xxx.xxx.xx.x 255.255.255.0
no ip redirects
no ip proxy-arp
duplex full
speed 1000
standby 1 ip xxx.xxx.xx.x
standby 1 timers msec 100 msec 300
standby 1 preempt
standby 1 authentication xxxx
standby 1 track 1 decrement 50

interface FastEthernet0/0
description LAN XXXX
ip address xxx.xxx.xx.x 255.255.255.0
no ip redirects
no ip proxy-arp
speed 100
full-duplex
no cdp enable
standby 1 ip xxx.xxx.xx.x
standby 1 timers msec 100 msec 300
standby 1 priority 95
standby 1 preempt
standby 1 authentication xxxx

In log on standby router, i can see the following message:

.Nov 20 09:21:37.398 CET: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Standby -> Active
.Nov 20 09:21:37.474 CET: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Active -> Speak
.Nov 20 09:40:38.154 CET: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Standby -> Active
.Nov 20 09:40:47.114 CET: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Active -> Speak

How can I keep from coming back? I force the port of switch to full duplex speed 100 and change the wire. Someone can help me?

Thanks

[emilio1973]

This is a show log on backup router:

.Dec  2 14:43:50.950 CET: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Standby -> Active
.Dec  2 14:43:50.950 CET: HSRP: Fa0/0 Grp 1 Redundancy "hsrp-Fa0/0-1" state Standby -> Active
.Dec  2 14:43:50.974 CET: HSRP: Fa0/0 Grp 1 Hello  in  213.190.6.175 Active  pri 100 vIP 213.190              .6.1
.Dec  2 14:43:50.978 CET: HSRP: Fa0/0 Grp 1 Active router is 213.190.6.175, was local
.Dec  2 14:43:50.978 CET: HSRP: Fa0/0 Grp 1 Active: g/Hello rcvd from higher pri Active router (              100/213.190.6.175)
.Dec  2 14:43:50.978 CET: HSRP: Fa0/0 Grp 1 Active -> Speak
.Dec  2 14:43:50.978 CET: %HSRP-5-STATECHANGE: FastEthernet0/0 Grp 1 state Active -> Speak
.Dec  2 14:43:50.978 CET: HSRP: Fa0/0 Grp 1 Redundancy "hsrp-Fa0/0-1" state Active -> Speak
.Dec  2 14:43:50.982 CET: HSRP: Fa0/0 API MAC address update
.Dec  2 14:43:52.178 CET: HSRP: Fa0/0 Grp 1 Speak: d/Standby timer expired (unknown)
.Dec  2 14:43:52.178 CET: HSRP: Fa0/0 Grp 1 Standby router is local
.Dec  2 14:43:52.178 CET: HSRP: Fa0/0 Grp 1 Speak -> Standby
.Dec  2 14:43:52.178 CET: HSRP: Fa0/0 Grp 1 Redundancy "hsrp-Fa0/0-1" state Speak -> Standby

[glen.grant]

   I'm not sure what you are tracking on the gig interface , if it's the serial interface and that is flapping  , with such low hsrp timers it's going to immediately cause a state change , maybe check that serial line.