DJWIG 0 Newbie Poster

hey guys i'm having a problem with pro tools LE 7.o I HAVE A G4 DESK TOP .THE SPECS IS 2G RAM 1.8GHZ IN PROCESSOR SPEED TIGER 10.4.6 IT KEEP GETTING AN ERA MESSAGE WITH PRO TOOLS THAT SAYS THE AUDIO BUFFER UNDER FLOWED IF THIS OCCURS FREQUENTLY,TRY DECREASING THE HV / BUFFER SIZE IN THE PLAYBACK ENGINE PANEL OR REMOVE OTHER DEVICES FROM THE AUDIO FIRE WIRE BUS [-6085].I INCREASE OR DECREASE THE BUFFER SIZE WHEN IT TELLS ME AN IT STILL GIVES ME THAT ERA MESSAGE

I DON'T KNOW HOW TO FIGURE IT OUT. IT IS SLOWING MY SESSIONS UP AN I'M NOT USING PLUG INS IS THE G4 COMPATIBLE WITH TIGER10.4.6 AN 7.0 PRO TOOLS CAN ANYONE HELP ME