First, there is no Premiere Elements 9.0.3 Update version of Premiere Elements 9. There is one for Photoshop Elements 9. So, I am assuming that the 9.0.3 was a typing error and that you meant to type 9.0.1 which is the required update for Premiere Elements 9.
There is an Adobe document on damaged projects that you might want to check out.
But the first thoughts that come to mind on a problem such as this
a. Have you moved or deleted any of the source media that went into any of these projects?
b. Can you still open a new project in Premiere Elements 9.0.1?
c. Is your video card driver up to date according to the web site of the manufacturer of the video card? Do you have the latest version of QuickTime installed on your computer with Premiere Elements, and are you running the program as Run As Administrator or from a User Account with Administrative Privileges?
d. Have you tried to delete the Premiere Elements 9.0.1 settings file (Adobe Premiere Elements Prefs) found in the path (for Windows 7, 8, or 8.1 64 bit)
Local Disc C
and in the 9.0 Folder is the Adobe Premiere Elements Prefs file that you delete. If that does not work to solve the problem, then delete the whole 9.0 Folder in which the Adobe Premiere Elements Prefs file exits. (Be aware that the Adobe Premiere Elements Prefs file (new) will be generated after you open Premiere Elements. Make sure that you are working with Folder Option Snow Hidden Files, Folders, and Drives active so that you can see the whole path.
Let us rule in or out the above considerations. And, if necessary, we will go into your computer environment, including optimization and the possibility of pile ups of preview files and conformed video and audio files. Are the Scratch Disks directed to a hard drive space with enough free space to accept them?/