Yesterday Firefox updated itself to 3.6.9 and starting this morning I have found that at random intervals while running it that my 5 pages in my home page selection are reselected and added. The first one ends up overwriting the page I am viewing while the remaining end up as new tabs.

This has happened twice this morning while I was viewing separate sites. In the first case it happened twice in immeadiate succession resulting in 13 tabs.