I attempted to upgrade LuceneSearch from 1.0.3 to 1.0.4.  I uninstalled via the button on the search module itself then from the exstension manger tried to delete the module. The delete process said it processed correctly but when the site refreshed I recieved an application error. I will be trying to replicate this on my testbed as soon as I can to provide more information.
 
Hi,
Can you give me your detailled error ? 
Best Regards,