This has happened to me before. What has worked for me is to simply download the toolbar again. When I have done this, I choose to "open" the file rather than "save" the file. I don't know if that really makes any difference but it has worked for me every time my Google toolbar "dissappears" (it has happened at least 3 times!).
I downloaded and installed Google toolbar. I have XP pro, IE 6.02, and download GTB from their own page.
I can see the checked Google option in the the view section, it just does not show up on my window bar. I tried unlocking the toolbar and moving things around, there is just no google on that menu. I have installed all the recent updates for IE. anyone have any ideas?