Hi,
I recommend upgrade to mojoPortal 2.3.9.7 and then rebuild the search index. The recent content feature uses the search index and there were some fixes in version 2.3.9.7 to help avoid duplicates in the search index. Those duplicates you see mean there are duplicates in your search index.
Also make sure you are not running the site with multiple host names on the same site or multiple IIS web sites pointing to the same installation because then the search index can be updated from multiple contexts which can create duplicates in the search index.
Also I notice you have CombineCSS set to false which I recommend never doing, it causes all the separate css files to be linked (which makes lots more http requests and is not good for page performance) and then you have no control over the cache headers of the static css files as you do when they are combined by csshandler.ashx.
Hope that helps,
Joe