Well, ok. Despite the fact that the file name suggests that this is a MS Word document (the .doc ending), it is actually a PDF file, displaying a calendar for September 2008.
I don't know how this mismatch might have occurred, but I can well imagine that it's confusing the situation a lot, since Windows depends on the file name ending to correctly match what's actually in the file.
OOo cannot open this type of file--a PDF is not a word processing document--so it falls back to the lowest level and tries to open it as a plain text file, and finally puts up the filter selection window.
You can fix some of the problem by renaming the file with the matching ending: sept.pdf
You can tell if a file named "something.doc" is really a PDF file, if when you open it in OOo (just click OK for the filter window), you see %PDF-1.4 as the first line.
Don't save the file from OOo--it will be ruined if you do--just use OOo to check what type of file it is. You can close the file and "discard" it.
Where are we at this point? I'm not sure now what you need to do.
AOO 3.4 • Linux • Fedora 17