Acrobat does not close completely; hogs memory

Hi, everyone. Perhaps you can help me out.

I have a 1-yr old Compaq PC running XP, but this problem has occurred on more than one computer.

Whenever I use anything that uses Acrobat Reader (like open a .pdf file I downloaded), when I'm done, I close Acrobat or the window the .pdf is in.

But my task manager continues to show AcroRead active, and it's generally using 10-20 MB of RAM. Naturally, this is unacceptable, and slows down my system quite a bit.

I have had this problem for some time, and have upgraded Reader at least twice while secretly hoping the problem would be fixed, but no dice.

So, any ideas?

Thanks!

General Tsao