Dear Morten, answer to your last question first:
What exactly is the "GNUmeric portable app version"?
http://portableapps.com/apps/office/gnumeric_portable You can obtain LibreOfficePortable there as well, for example. In this context, "portable" means that you can run a "portable" app from a USB stick attached to any PC running a recent version of MS-Win, and take all your personal settings with you; no administrative privileges neccessary for installation, no registry entries etc. very handy for the "mobile workforce"... of course, portable apps might use code of Win standard libraries.
We are not supposed to have anything like magic brackets. We don't even have code for it.
I appreciate this opinion very much, as I hate "unkown unknows"... Here's the link to the paper in which W. Kahan complains about this phenomenon: http://www.cs.berkeley.edu/~wkahan/Mindless.pdf The "magic bracket" subject is treated in "ยง2: Errors Designed Not To Be Found" on page 3 ff. I used the 1/2^n approach in order to find out how many trailing bits are cleared.
Could you please file a bug for this at bugzilla.gnome.org with a test sheet?
I promise to do that this weekend; I'm a bit busy right now because I'll leave for a two days business trip tomorrow morning. Please find attached the Win-version of my sheet. My Linux-GNUmeric was able to open it (sorry, but I'm on Win now and in a hurry...). All the best Schorsch
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