Unable to fetch search index words

I am receiving the following error whenever I make a post. 

Unable to fetch search index words

I receive the same error trying to rebuild the search index.  Is this an SQL error or an error with the webhost?  (The webhost recently installed mod-security on their servers and I jave been receiving internal server errors on various websites with forums running punbb, phpbb and invision power board when making a post - apparently they have to confugure things and include your forum on a white list)