Aargh!? Tracks sound different post rendering

[bootc]

I'm working on voicetracks for broadcast and I've been having trouble with the tracks sounding diferent after they've been rendered. I'm using the Waves L3 to maximise and I have it sounding slammed but not distorted. After I bounce the track, import it back into the session and switch off the plugins so it doesn't get double processing, it sounds distorted.
I thought what you hear is what you get on the bounce??

Perplexed. . .

[DJ Insomaniac]

Try taking the L3's output and putting it down a few dBs, to allow for any levels that may somehow sneak past the limiting. See if that helps.

[bootc]

I've remedied the situation by rendering through a mono master although when I import the rendered track back into PT to have a look, it sounds fine but it's down -3 or -6db
Why is that?
Simon.
Btw, the L316 Multimaximizer is amazing!