99 Camry-New Battery and all heck breaks loose..

We replaced the battery in our 99 camry-no muss/no fuss but when we insert and turn the key the 4-way flashers come on even though they are not actually turned on !! Dash lights seem
to flash as well(like the clock). They do this for a few seconds,,stop,,then start again almost
immediately. The Camry engine will start but this vehicle would look like a christmas tree
going down the road ... lights flashing..etc.

Whats up ??
Thanks !!!

edit...

..after further analysis, the lights flash for 3 cycles lasting 30 seconds each and then stay off
until the car is turned off,then started again. So.... i think we're dealing with a 'ghost' alarm
problem that became active when we changed the battery since we are not the original owners
of this car. Oddly enough the horn does not beep at all-maybe the original owners had that disabled
or something. I did try the various 'hold the odometer button down..etc' methods i found on
the net for re-setting the computer and none worked but at least the car is driveable-we just
wait the 90 seconds until the flashers stop their dance and then go where we have to go. i'll
give the local dealership a call tomorrow(spent $900 there last week on my pickup) and hope
they can give me some advice.