LO 4.0.2.1 Windows 7 Professional

I tried to reproduce this, by typing in the formula you gave as an example, in a blank sheet.
On my system, the cell displayed on the screen is not blank, but contains the text that you describe as only appearing when printed.

Perhaps the bug is that the value is not appearing when editing the document, when it should??

My fault,

I forgot to mention that the bug is present when you have "Display Zero Values" unchecked in the options. I.e.,

Options -> Calc -> View -> Display Section -> Zero Values

This option effectively disables the display of zero values, but does not disable it in printing or exporting to pdf. Changing bug title accordingly.

Duplicate of an ongoing "bug" that is being discussed:

*** This bug has been marked as a duplicate of bug 51856 ***

Unhappy about duplicate status.

My issue is not that the option not to print zeros is hard to find in the print menu, or that it is not persistent.

My issue is that the system is inconsistent. It may not show the zeros when editing and then print them. When you ask not to see the zeros, IMHO by default the zeros should not be printed either.

If we ever make a mistake, feel free to undo our change ;) We're all human. Removed duplicate status - will investigate further. Thanks!

Thanks for removing duplicate and for the advice. I didn't know if removing the duplicate myself was OK!

It is okay as long as you justify the change :) Which you seem to have done

Goto menu Format > Page > Sheet > unchek Zero values under pane "Print"
And then check with Page Preview

Please change status to: RESOLVED NOTABUG if you agree

It is not that important and I can forget about this bug. But again... the bug (which is a minor usability bug) is about interface consistency.

Why are there 2 different places where one decides where to have or not visible zeros?

One is in tools->options->calc-view (and affects display)
Another one is in format->page->sheet (and affects print and export to pdf)

IMHO this is causing confusion in the users (at least in my and some users I used to prepare templates for), because:

1) When a document displays in some way, users expect it to print in the same way. Aren't they using a wysiwyg software just for that?  It is confusing that they have no zeros in display and then zeros suddendly appear when they print.

2) These options are (correctly) buried under a 3 level hierarchy. Unfortunately this makes them not exactly easy to find (also due to the fact that the first levels of the hierarchy are quite different). Thus, when the users have their systems not showing the zeros and then get funny printed documents filled with zeros, they may get frustrated before finding what to do.

I wonder if there a reason why this needs to be selectable in two different places in this way? I can think of cases where one may want to see zeros and not to print them (because in editing one may want to know if a cell is empty or not), but I really cannot figure out a case where one may want to print the zeros but not to display them.

This is not a bug - despite perhaps being a little confusing it's designed and behaving as expected.

One could easily argue that there are times when you want to not see 0's on the screen but when you print you do OR that you want to see 0's on the screen but not when you print.

For the case that you said you can't imagine why you'd want it. You could argue that on screen it gets quite cluttered when you have a lot of 0's but once you print you are intending for the audience to see the 0's, even if it's cluttered the 0's mean something that you want your audience to see.

Fundamentally these are two different options, combining them takes away usability and I am almost guarantee that if we combined them we'd have users unhappy with stripping them of the option(s).