I have a similar, or possible worse, problem. For some reason some of my pages get rewritten newsitem-2.html when they were origianally written newsitem.html and are indexed in Google as newsitem.html, but now that URL has gone because it has changed. Purging SEF URls doesn't work, some URLs still get rewritten with a number 2 instead of just .html. THe only way I can fix it is to use PHPMyadmin to empty the redirection table, which is a total pain because it keeps happening all the time. I can't have my content changing it's address in this way because it will never be indexed by anyone.

I'm also having the exact same problems and was seeking an answer the the previous poster's question.