How create video captions (titles) in video using Adobe Premiere 6.5?

Hi,

Ihave created a video and I want to put captions on the bottom of some parts describing the place or the person talking.

I followed the help files and created a title, added it to the timeline but when I play-back on the monitor the title does not appear in the clip, instead for a moment the screen flashes black with a red "X' in the center and it passes over the title in the storyboard.

I tried adding transitions and the same thing happened.

What am I doing wrong?

Thanks