It definitely seems that there is a problem with your install. Since you have tried the cache file and re-installing doesn't work you should try renaming the configuration folder to see if that helps to resolve the problems. Here is a link to the steps to do this.
If the problem persists please let us know. Also, are you interacting with the interface using your mouse, or the keyboard, or a combination? I have seen some problems occur with the selection not being retained if you use the keyboard and the enter key to confirm selections. Please let us know how this goes for.