Cubase LE 5 Sample Editor Freezing UP

Hello, my name is Will and I am using Cubase LE 5 and every time I am in the Sample Editor and try to do anything with the Hitpoints or try to listen to a part the whole screen turns WHITE but I can still see what I am doing. If I don’t click on anything the whole entire track will keep playing until I try to click on something. I get no response for a few minutes then I get " PROGRAM NOT RESPONDING". If I just let it be after playing the track a few times the screen will turn back to normal like nothing ever happened. This occurs every time I am in the Sample Editor with every song and every track. Audio Part Editor is always fine. Has this happened to anyone else out there? Is there something I didn’t set up right?
Also I want to upgrade to Cubase 6 but I am wondering which version is the best for a beginner like myself. What is the best way to do it, can I upgrade from LE 5 or do I have to purchase a completely new version?
Thank You in advance and any bit of information will be much appreciated.

I’m not so sure about your crash problem. Which Windows version are you using?

As for Cubase 6: that’s a bit difficult for us to judge :p. It really depends on your needs! What is it that LE5 can’t do you’d like to have? I suggest you have a look at this, and then this.

Upgrading is always cheaper than buying a new product, so if you can you should do that. (unless you want 2 separate licenses so you can use LE5 and your new version simultaneously. Note how your upgraded license can still run LE5 too, just not at the same time.)
If you decide on getting Elements 6, you can’t upgrade from LE5.