Screens Opening Randomly

Hey everyone. This is my first post so please be patient.

I have a MacBook Pro, running the new Lion OS. Recently, screens / windows have been opening randomly while I'm working on my computer. I'll be typing in Word and all of a sudden, 10 documents that I haven't worked on in months will open up one by one. Or a Preview will open up with a file I haven't worked on recently. I'll also get multiple Finder screens opening up randomly. This is starting to freak me out - it feels like there's a ghost on my computer. Anyone know what's going on or how I can make this stop?

Thanks!

You may have 2 problems here, but the first is...

You must close your documents before Quitting the Application, otherwise they will reopen when it next opens, and yes I agree, its a where did that come from moment as something you had open weeks ago reappears.

We are moving to a model with no Quit, just close and like the iPad/iPhone the Mac will decide when it needs to Quit an App, not us.

I appreciate your reply. This somehow doesn't feel like the problem to me as I'm also experiencing random changes of formatting in my Word documents while this is happening. It is literally like someone else is using my mouse sometimes. You said there could be two problems...what might the second be?