This may also work, although it requires a journey into Terminal-land.
Let's assume that the document in question is called "myfile.123", and that it is read only, and that it is in your home directory. If it isn't in your home directory, please move it there before proceeding. Let's further assume that your userid is "myuserid".
Start Terminal.app (from your Utilities folder). Enter the following command:
This command changes the permission bits of the file, in this case turning on the write permission bit. This may resolve the issue.
If you get an error from this command, try this next step. Enter the following two commands:
Code:
sudo chown myuserid: myfile.123
(enter your administrator password when prompted)
chmod +w myfile.123
The first command changes the owner of the file to yourself. The second is the same command from above.
With any luck, one of these two will do the trick for you.