[TYPO3-Solr] Highlight the title of my content

[Sergio Catalá]

Hi list,

I just want to higlight the title of my content in results list page. So 
I setup:

plugin.tx_solr.search.results {
     resultsHighlighting = 1
     resultsHighlighting.highlightFields = title.content
}

"content" field is highlighted with the query search terms, but not the 
"title" field.

Do I need an extra configuration in solrconfig.xml on my server?

I read something about fragment sizes, that it could affect this problem.

Can you give me a hint about that?

Thanks in advance,
Sergio