O OpenOffice no linux não detecta mesmo os scanners...
http://www.bytebot.net/openoffice/faq.html#Package14.2. How do I get my scanner working under OpenOffice.org?
In Windows, this is as simple as Insert -> Graphics -> Scan; as long as you have a working scanner with TWAIN support, you're fine.
In Linux however, there is no direct scanner support. The source can't be detected, so a workaround is to scan an image via The GIMP and then import the image via Insert -> Graphics -> From File. However, if you're willing to get your hands dirty, as the root user on Linux, perform ln -s /usr/lib/libsane.so.1 /usr/local/lib/libsane.so and the scanner will start working! (What that does is that it makes a soft-link called libsane.so; if your libsane.so.1 isn't located in /usr/lib, just execute a "locate libsane" for instance to find it).
Eu nunca gostei de escanear direto nos programas. Costumo escanear tudo o que preciso primeiro e depois insiro as figuras no texto a partir dos arquivos gerados antes.