Excel 2007 :: Redo And Undo Broken After Save?

I have Excel 2007.

Undo / Redo - they do NOT work properly after a save. Before a save, its great - I can undo / redo many many changes.

After a save, I can only undo 2 changes, but the worst thing is it ONLY REDOES ONE of them.

I work by saving very regularly, then I go and look at something on the sheet, and then use Undo / Redo to get back to where I was last updating the sheet and see what I had just been working on, especially if its a few minutes in between.

However, when I do that now, it undoes my last change, but the redo has been lost. So I do:

change, save, undo, redo

and it just doesn't do the redo. The redo button is greyed out.

If I do:

change, change, save, undo, undo, redo, redo

the first redo works, and the second fails as the redo has been lost.

It seems pretty basic that undo / redo should be symmetrical but they aren't, at least now.

I would rather just not have undo after save at all than this broken version.

Why are they putting so much stuff in Excel but they can't even get one of the most basic parts of spreadsheets correct - such as undo / redo, and the ability to open independent spreadsheets without having to change things in the registry (which I have had to do so I can work on two spreadsheets in a semi-sane fashion, undo being shared across your sheets otherwise). MS needs a back to basics...