I think my problem may be related. I run three sites, http://www.militarymodels.co.nz, http://www.wwimodeller.co.nz and http://www.wwiimodeller.co.nz. Exact same settings on all three sites. WWIModeller and WWIIModeller no problems (so far). Militarymodels only works completely in Chrome. In Explorer, Firefox and Safari several widgets dissapear from the left sidebar (including categories and links) on the home page but appear on other pages. When the categories widget does appear the category links then only show posts up until the end of May.
Don’t get why it only effects one site.