If you've done mail merges before, you've seen this message.
What you should do, every time, is to click Yes and leave everything else alone. Then the mail merge will print with the contents of your data source.
What would make sense is to mark the Do Not Show Warning Again checkbox and click Yes, thinking that every time thereafter you'll be able to print the mailmerge correctly, with the contents of your data source, just like you did this time, but without that pesky message popping up.
You'd be logical, but you'd also be wrong because of the wacky design of the program. If you mark the checkmark, then from that day forward you will print, instead of a mail merge, a list of fields like <Firstname> and <Lastname>.
How do you get that dialog box to come back so you can print a mail merge correctly?
Answer: Here's how it's supposed to work. People say this works. I can't find a file with the relevant flag in it on my machine but if it works for you, great. It should work.
<< Reader David Beroff offers some fine suggestions after his successful implementation, which I have updated the instructions with.>>
1. Close OpenOffice.org.
2. Find the Writer.xcu file. It's in one of these locations.
Documents and Settings\[users]\Application Data\OpenOffice.org2\ user\registry\data\org\openoffice\Office\Writer.xcu
3. Make a backup copy of it. Just copy the file in your file manager and paste it somewhere else.
4. Open it with an Ascii editor (i.e Notepad or 1stPage or some such program.)
5. Look for <prop oor:name="AskForMerge"> and set the value to true. To do this, look for "AskForMerge=False" and type "True" where it says "False."
6. Save the file.
Now you'll get the message popping up again when you print a mail merge. Leave the checkbox alone and click Yes, and you're golden.