Cannot unbold text from word

Hi,

I convert word file to HTML (with external library) and then I load it to CKEditor. But if in word file was Bold text I can't unbold the text in CKEditor (it is also problem with italic and underline). This is part of HTML which is loaded to CKEdiotr:

<span style="font-family: Arial; font-size: 10pt; font-style: italic;
                    font-weight: bold">«PISMO_DATA_2»</span>