echo when recording mostly on intel systems

[Litemup]

back in 04 i had a sony (intel p4 2.0 1.5gb of ram) with acid work great so i call myself stepping up so i went out an got 002 rack[pt 6.1] my whole hood was happy i felt like the man but when i start to record ppl they said they heard an echo there voice lagged by like a half a sec or something trying to fix the problem i killed the vaio [my first luv] so i put together an amd 1.8 2gb pf ram. then the ppl stop hearing the echo. i killed my second luv with gta san an
now it 08 an im on a imac intel 2.8 2gb of ram with an 003 factory an the echo is back? is this just pro tools on intel because the other DAWs works fine

[OddsAre]

is your "Low Latency Monitoring" setting engaged? under options?