Thanks terpe for the information...

I also found these in the italian embassy's website..

According to EU Directive 2004/38/CE, family members of EU nationals, who do not have the nationality of a Member State, but have UK Residence Permits issued by the British Home Office bearing the specific following indication: "RESIDENCE DOCUMENTATION Type of Document: Residence Card of a Family Member of an EEA National" will not need a Schengen visa for a SHORT STAY (up to 90 days in 6 months) in Italy if accompanied by the EEA National OR if travelling to join them. Bringing a copy of marriage certificate or proof of relationship is advisable. Any other wording on your UK Residence Permit indicates that you need a visa.

Please note: if the applicant (husband/wife/children/dependants of Italian and EEA nationals) is travelling ALONE (i.e. without the Italian or EEA national) he/she must submit all the required documents as an ordinary applicant and he/she is subject to the visa fee.