[CentOS] Problem when opening files after installing OpenOffice 3.1 on CentOS 5.4

I did some tests today:
- removed/reinstalled OO 3.1 from RPM => did not solve the problem
- updated /usr/share/applications/defaults.list as per Janez advice =>
did not solve the problem

Interestingly I have this issue with ODT files but not with ODS
(spreadsheets) files.

I'll keep digging  (maybe on a clean virtualized install) and let know
here (any ideas still welcome!)