Cannot ack hobbit alerts

Hi guys,

Have recently upgraded to 4.0.2 and discovered we are having some issues
ack'ing alerts this morning.

Its sending out notifications to email and pager fine but when I put them
into the Ack Alert page on hobbit it says alert ack'ed or whatever it says
but theys till keep coming. Also in the hobbitd.log i get the message

date time Cookie 624644 not found, dropping ack

There is no way I've typed it wrongas I got 4 ppl to look at it to make sure
I wasnt going insane.

Also not sure if anyone else has had this since upgrading to 4.0.2 as my
emails for the last few days seemed to have vanished

Allan