That seems a long time.
Have a look at these links, I can't help much more, but I'm sure someone more knowledgeable will be along soon.
Good luck.
Faster Load Time
OpenOffice.org developers have streamlined the code to improve upon the time taken to initially load the suite. Also, a progress bar has been added to the splash screen.
http://www.openoffice.org/about_us/1..._releaseb.html
http://www.openoffice.org/dev_docs/instructions.html
Forgot to add
Note:It is NOT advisable to install over an existing OpenOffice installation. If you want to use the same destination as an existing version of OpenOffice, delete the contents of the existing directory!