Can't open a password protected file

I have a password protected calc file that I’ve been using for over 6 years (it was originally an openoffice file) and suddenly today it is rejecting my password. Is there any way I can get this open? Help!

http://www.libreoffice.org/download/3-5-new-features-and-fixes/

Different Encryption Algorithm

In LibreOffice 3.5, a different, more often used encryption (AES) will be introduced to replace the previously used one (Blowfish).In consequence, files encrypted with LibreOffice 3.5 can not be opened by LibreOffice 3.4.4 and earlier. LibreOffice 3.4.5 enables you to open those files. However, on saving again in LibreOffice 3.4.5, the old encryption will be used. Files with the old encryption of course can be used in LibreOffice 3.5.0
Related issues: fdo#43868 and fdo#40006.

Thanks mariosv. That was the problem. Different computer with an older version of LibreOffice.

Do you need to crack the PW or is your problem a different one?

just upgraded to fedora 19 which now runs 4.1.0.4 build id: 4.1.0.4-5.fc19
was opening my xls password protected sheet in fedora 18 (sorry dont know the version there but i think it was 3 something) but now libreoffice says that it is corrupted
i can open the same file from dropbox on a windows machine which i did then saved it as xlsx but it wont open in the new version of libreoffice
is there any way around this?
the file is .xls and .xlsx formats but neither will open in libreoffice

OK. This seems far from solved to me! I was able to get it working again on my Mac.

I’m using OpenOffice 3.4.1 on MacOS 10.6.8

Had the same thing going on. Tried a few of the suggestions with no luck.

Went to http://www.oldapps.com/mac and downloaded OpenOffice 3.0.0 here http://www.oldapps.com/mac/openoffice.php?old_openoffice=9661 BEWARE of all the links on the page that are advertisements to other downloads and look like the right button to press!

I then when and tried to open my password-protected file through OpenOffice 3.0.0. I didn’t know it, but I got an old version of the file that was probably in Excel. The old version of OpenOffice crashed a couple of times trying to open it. Then I found I could open the .ods version of the file in OpenOffice 3.4.1. So it was probably just installing the older version and starting it up that mucked around with the necessary files, I guess.