Payment Requisitions

Some of our client computers (not all) cannot open the "update this period" box.  One is running Vista and the other is running windows 7.  We are using Contract Manager 14, but this problem was happening before we upgraded from 13.  My computer opens it with no problem, I am running XP.  One person commented that at one time he could use it with FireFox and not IE and then it changed and he couldn't use it with FIreFox but it worked on IE, now he can't use it at all.  Our server runs SBS 2008 but the problem was