Updating from 7.8 to 7.13, missing text attributes


I have updated the CRM from 7.8 to 7.13 step by step semingly successful. All seems to work OK but the text attributes such as <s> </s> or <b> </b> only work correctly in the case view not in the customers view. In the customets view the tag is printed out instead of the effect. I am not sure where to look for the issue in CRM, can someone point me in the right direction ?

Thank you!
Jan P.