Hi,
I am not able to produce this problem on my local machine nor on demo.mojoportal.com
Please make sure you have these settings in your user.config file:
<add key="SearchUseBackwardCompatibilityMode" value="false" />
<add key="DisableSearchFeatureFilters" value="false" />
<add key="EnableSearchResultsHighlighting" value="true" />
If not then add them, then touch your Web.config to recycle the app, then rebuild the search index.
Hope it helps,
Joe