It's very strange that you have the problem even after creating a new project. The new project can be completely blank and you shouldn't ever be prompted to open a temp file.
Two more ideas come to mind. Under the Preferences (gear icon), go to the Project tab and uncheck Automatically load last project, then close PD and try opening it again.
If the problem is STILL there, you should fully uninstall PD (and QuickTime and SmartSound, if prompted) and then reinstall using the original DVD or downloaded installer files. You'll need to have your license key but your issue should be solved.
After reinstalling, be sure to get the latest patch for PD (3130) and update QT to v7.7.8 from www.Quicktime.com
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