two series of 3 beeps- what is it?

When starting my 2000 Grand Cherokee Limited 4x4, 4.7v8 just when you think all the buzzers and bells for seat belts etc are finished I get a series of 3 beeps. This happend twice at each start. No indicator lights are on and I have not been able to find anything as to what these beeps mean. Anyone know what these mean? Autozone checked for codes and their reader said system good.
Thanks for you help.

Three short beeps would be Morse code for letter "O", three long beeps would be "S". If it starts doing three longs, three shorts, and three longs, it is asking for help. (Save our Ship) LOL

Not to be a pain in the arse, but you may want to ask this question on a Grand Cherokee forum. This forum is specific to XJ Cherokees, none of which are equipped the same as your V8 Grand.

My Sony radio does that when I turn the ignition off. Its supposed to be a reminder to take the face off the radio. Be nice if you had the option to turn that off though.

BTW, a quick google search turned this up.
http://www.fixya.com/cars/t1521260-perform_maintenance