today we had a failover event on a pair of asa5505's running 7.2(4). The standby took over fine and no impact was seen to traffic, strangely, after 58 minutes the primary came back and took over. Running show fail on both units gives the correct info for the standby, but the active unit reports that it has not failed since April (installation date). The switches show no interface problems or anything that could have caused failover, the failover link is switched and no bounce there either.
Basically, the unit has ceased passing traffic for no apparent reason, failed over and then not has recorded this failover to show in the show fail output on the primary.
Has anybody ever seen a similar problem with 5505's running this code, I can't seem to find anything untoward in any of the output or from the logs on the switches?