HSRP on 3640

[l.motta]

We have 2 3640 on hsrp statement through Catalyst 2950 and Allied switch.

Every day at same time , one of those continues to change standby group from STANDBY to SPEAK without any HSRP change on other router.

I haven't found any BUG for this problem.

Someone can help me,pls?

[rtappend_2]

At the time of the transition, is there any peak traffic load? eg any congestion or dropped frames on the switches?