On Thu, 20 Oct 2005, Tom Cadden wrote:
Unfortunately it is more common than we realise. From nonsensical 'factoids' that are made up to completely ridiculous articles. I came across one page recently on a prominent early 20th century politician. It was twelve lines of paranoid, POV garbage. It had been sitting there for months. If anyone thinking about joining Wikipedia had stumbled across the article as their first experience of the site I wouldn't have blamed them for saying "if this is what this so-called encyclop�dia publishes, it is obviously a heap of crap" and left Wikipedia. Even when I rewrote it the vandal kept coming back to reinsert his garbage. When I left for a few weeks he came back again, put back the rubbish and it survived unnoticed until I came back and saw it on my watchlist.
First, what you're encountering is not vandalism: it's someone pushing her/his POV. All of us do that on Wikipedia, whether what we write is paranoid garbage or not; whether we are successful should depend on how we agree to disagree on the subject -- although it sometimes doesn't.
Second, take a look at Wikipedia's steps for conflict resolution: your situation is why these steps have been created. Start at the far end of complaining to the ArbCom, & I'm sure one of these steps will solve the case. (A fair number of these kinds of agreements come to a resolution just by simply asking another person to join in the conversation.)
Geoff