Adobe and MS Internet Explorer

Our agency accesses several different internet sites at the same time. Some secured and some not. Within these sites are adobe forms that can be emailed to perspective clients. They access databases and bring up specific information. Some of my users while having several of these sites open will try to email the adobe doc using the icon on the tool bar for adobe and the their pc will lock up. Can having too many sites open with a mixture of secure and unsecure access cause conflicts so that adobe locks up a pc?