If you spend a lot of time using OpenOffice, editing files over an NFS share, then you may occasionally run into a problem where all of the sudden OpenOffice thinks all of your *.odt files are read only. The quickest way to get around this problem is to edit the soffice OpenOffice startup script directly.
Somewhere near the top of the script you will find two lines that look like this (first line doesn't count as it's commented out):
# file locking now enabled by default
SAL_ENABLE_FILE_LOCKING=1
export SAL_ENABLE_FILE_LOCKING
You want to edit the soffice file and comment out both the SAL_ENABLE_FILE_LOCKING=1 and the export SAL_ENABLE_FILE_LOCKING line. Save the soffice file, restart OpenOffice and you should be able to write to your *.odt files again over NFS.
Now with file locking out of the way, you will need to make damn sure that no one else is editing your files over NFS at the same time you are.