Have you tried scrolling down the timeline view?
Have you tried right-clicking on the timeline and selecting the option to remove all empty tracks so that you're not using more vertical space than you need to?
Yes, tried all that thank you. i reset my mac to 5 weeks ago yesterday, then opened PE13 and all was ok so did a bit more editing. Come on this morning and back to my problem.
Can you please post a screen capture of your interface so we can see what you're describing? There may be something you're not seeing.
BTW, you have gone to the Window menu and select Restore Workspace, right?