I don't really remember when the bug started to show, but it was today that I realised it, so I guess the problem must be with the current version (1.1.4-3), since I did an upgrade a few days ago.
In this case the problem is specifically with dead keys. The ' key works with every X Window application but OpenOffice.org. It doesn't function as a dead key at all and so accented characters don't show. the ñ key works though perfectly, and every simple AltGr+key (Right ALT) combination works too. I'm currently downgrading to stable (sarge) version (1.1.3-9) from etch repository. See?, works perfectly now with OpenOffice.org 1.1.3-9. It's a sid-only (1.1.4-3) issue. :-)