Need help with deleting part of track

[El_Siesta]

On some tracks, if you've moved them, and a small part of the track goes behind the 0:00 mark, it stays there, even when i try to export all the tracks to WAV, they don't align correctly because of the few second that are added to the tracks that have a small part of them moved behind the 0:00 mark.

Is there a way to delete this?
I have alot of tracks i need to export and doing it all manually would be a royal pain in the ass.

Here's a picture showing the arrows indicating that the track has been moved behind the 0:00 mark.

Hopefully you can understand what i'm trying to explain.

[kozikowski]

You can get this effect if you tell Audacity to only cut or process on zero-crossing boundaries. If there's audio "sticking out" to the left of the selected edit point, it can be pushed earlier than time zero.

I can't find that preference setting, but I'm still looking. Koz

[kozikowski]

It won't come back even if you use the Time Shift Tool -- two sideways black arrows?

Koz