After 2 hrs of brain storming on weekend in my office finally got spell checker working for my open office 3.2 on ubuntu 10.04. i had to take expert help from Hobbes, nigleb and lastly Indranil dada and it worked.
sudo apt-get install hunspell myspell-en-us openoffice.org-help-en-us
Once this is installed open a open office document and TOOLS -> OPTIONS –> LANGUAGES
Once this is done check WRITING AIDS and do as screen shot does. 
Restart your open-office and you will have spell checker working.