Can't extend light green area of timeline for animation in Photoshop cs5

[Shaun27223048ebob]

Hi,

How do I extend the light green area of a layer in the timeline to the left, please?

Also, some text in my animation refuses to show in the gif, regardless it displays when I play the animation through in PS, and regardless other near identical text layers appear. Are there any reasons why this might occur?

Here's a screenshot from PS:

And here's the animated gif:

Thank you for your time and help.