No Latency?

[seawell]

Hi, I'm new to Pro Tools( I have owned a Digi 002 Rack for about 2 weeks now). I have been mixing a project that was imported from a Radar 24 into Pro Tools. My computer is a G4 IMAC(1GHZ, 1gigRAM) running OSX 10.2.8. I have heard many tales of latency issues, is this mainly with tracking or also with mixing? The reason I'm asking is that in one particular mix I'm working on I have 4 plug-ins inserted on a vocal track(auto-tune, BF LA-2A, D-Verb, and EQ)....I assumed with running this many plugs on one track I would have to nudge that track but when I command click on volume, the delay readout says "0." I know my computer is decent but it isn't super fast so this surprises me. I don't hear any noticeable latency but I was just wondering if my delay readout is accurate. By the way my computer usage setting is at 85% , the H/W Buffer size is 1024 Samples, and the DAE Playback Buffer is set to level 2(default). Thanks for your help.