Unable to save ANY types of files in Elements 5.0

Question

Today I was working with Elements, creating a photomanipulation. This involved several layers, including a background of a beach, a horse, and some text. I've done this before with this exact same program on this exact same computer and not had too many problems. But not today.
Today when I try to save my creation, in ANY format, I get this message:
Could not save as
"C:\Users\User\...\Untitled-1.jpg" because the file is already in use or was left open.
GAHH!!!! Well of COURSE the stupid file is open, I'm working ON IT and trying to save my work!!! If I try to close the file, I get the standard question:
Save changes to the Adobe Photoshop Elements document "Untitled-1" before closing?
to which if I say yes, I get the same old crap:
Could not save as
"C:\Users\User\...\Untitled-1.jpg" because the file is already in use or was left open.
Now if I select save as *PSD or *PDD, *SOMETIMES* it acts like it has saved my work, (Instead of just saying it can't) but when I look for what I saved, all I find are a bunch of crap files that can't be opened. Example:
Cannot open 'C:\Users]User\Pictures\Photo Manips\~ps2AA0.tmp' because it is the wrong type of file.
Please note that I never actually chose to save ANY files called ~ps2aa0.tmp at any point in this process.
So I am stuck in a vicious cycle where before everything was working just fine. And it's not just editing photos or doing manipulations. I can take a brand new blank canvas, scribble a line on it with a paintbrush, and I am completely and totally unable to save even the simplest thing in ANY format whatsoever.
I tried uninstalling Elements and reinstalling it and that did absolutely nothing, except cause me to lose all the special effect brushes I spent hours downloading. And when I started it back up, I was right where I was before, it even had the same custom color preloaded on the palette, as if it did not truly uninstall AT ALL. (Just the special brushes were missing, thanks for nothing!)
My computer is maybe 8 months old now, a nice Hewlitt Packard with Vista. I specifically bought this computer so I could do more things with my art and more photos, and the first thing I loaded on it was the Bamboo tablet by Wacom, which came with Photoshop Elements 5.0 free. I've been using it ever since with hardly a problem and now today, I can't save the simplest little thing, and it is really aggravating me to death.
ANY light that anyone could shed on this would be most appreciated. I'm sure it's something extremely stupid, like I found the secret invisible "do not save anything ever again" button and somehow managed to press it. Whatever it is, I can not for the life of me figure out how to make it work like it's SUPPOSED to work. Somebody please help me before I go stark raving mad.

Answer 1

Further note: I have uninstalled this stupid program now THREE different times, including using a registry cleaner, which then deleted my DVD drive, thankyouverymuch. And even after I got the DVD drive back so I could reinstall the program, it was like I'd never uninstalled it (with the exception of the custom brushes still being missing) right down to the canvas size and paint color I had been using when all this started.
So uninstalling it does nothing, resetting preferences does nothing... I can not save my work, period. I've been fighting with this for about 8 hours and I am so frustrated I could just throttle someone with my bare hands for putting me through this crap.
For a product that came bundled with a $200 graphics tablet, it sure isn't worth a damn. Anybody got any ideas? I'm at my wits' end here.